TYPO3 Core

I did it for our installation and it's simple.

I hope I'll add the patch for TYPO3 soon, as long here is the code so someone else can do it as well.

You have to add the PHP Part to render the input form for suggest. Add the JS to implement the suggest, and register the wizard in TCA.

    $TCA['sys_template']['columns']['include_static_file']['config']['wizards']['suggest'] = array(
        'type' => 'userFunc',
        'userFunc' => 'EXT:' . $_EXTKEY . '/Classes/Tca/Wizard/SuggestWizard.php:Tx_ExtensionKey_Tca_Wizard_SuggestWizard->renderSuggestSelector',
    );

<?php

    /**
     * Add suggest wizard for select with item configuration.
     *
     * This will use the configured items instead of an Ajax call with select.
     *
     * @author Daniel Siepmann <daniel.siepmann@typo3.com>
     */
    class Tx_ExtensionKey_Tca_Wizard_SuggestWizard {

        /**
         * Render the suggest selector.
         *
         * Called by t3lib_TCEforms as userFunc Wizard.
         *
         * @author Daniel Siepmann <daniel.siepmann@typo3.com>
         *
         * @param  array $params The available configuration.
         * @param  t3lib_TCEforms $tceForm The current tce form containing the field.
         *
         * @return string The needed HTML. The needed JS will be added to t3lib_TCEforms directly.
         */
        public function renderSuggestSelector( array $params, t3lib_TCEforms $tceForm ) {
            $extensionName = str_replace( 'Tx_', '', __CLASS__ );
            $extensionName = t3lib_div::camelCaseToLowerCaseUnderscored(
                substr(
                    str_replace( 'Tx_', '', $extensionName ),
                    0,
                    stripos( $extensionName, '_' )
                )
            );
            $params['fieldName'] = 'data[' . $params['table'] . '][' . $row['uid'] . '][' . $params['field'] . ']';
            $html = t3lib_div::makeInstance( 't3lib_TCEforms_Suggest' )->renderSuggestSelector(
                $params['fieldName'],
                $params['table'],
                $params['field'],
                $params['row'],
                $params
            );
            $config = $params['fieldConfig']['wizards']['suggest'];
            $selectedItems = explode( '|', $params['row'][$params['field']] );
            $jsObj = str_replace( ' ', '', ucwords( str_replace( '-', ' ', t3lib_div::strtolower( 'suggest-' . $table . '-' . $field . '-' . $row['uid'] ) ) ) );

            $tceForm->additionalJS_post[$extensionName] = '
                var ' . $jsObj . ' = new TCEForms.Wfp2Suggest(
                    "'. $params['fieldName'] . '",
                    "'. $params['field'] . '",
                    "'. $params['table'] . '",
                    "'. $params['uid'] . '",
                    1,
                    [' . $this->formatItems( $params['fieldConfig']['items'] ) . ']
                );
                ' . $jsObj . '.defaultValue = "' . t3lib_div::slashJS($GLOBALS['LANG']->sL('LLL:EXT:lang/locallang_core.xml:labels.findRecord')) . '";
            ';

            $html .= '<script src="../' . t3lib_extMgm::extRelPath( $extensionName ) . 'Resources/Public/JavaScript/Backend/SuggestWizard.js' . '" type="text/javascript"></script>';

            return $html;
        }

        /**
         * Format items from TCA for usage inside the JS of the suggest Wizard.
         *
         * @author Daniel Siepmann <daniel.siepmann@typo3.com>
         *
         * @param  array $oldItems The original items as configured in TCA.
         *
         * @return string The items ready for usage in JS.
         */
        public function formatItems( array $oldItems ) {
            $newItems = array();
            foreach ($oldItems as $item) {
                $newItems[] = '["' . $item[0] . '", "' . $item[1] . '"]';
            }
            return implode( ',', $newItems );
        }

    }

/**
 * Add suggest wizard for select with item configuration.
 *
 * This will use the configured items instead of an Ajax call.
 *
 * @param  {object} window    The window object of the browser.
 * @param  {object} document  The document object of the browser.
 * @param  {undefined} undefined Just undefined
 *
 * @author Daniel Siepmann <daniel.siepmann@typo3.com>
 */
(function( window, document, undefined ) {

    if (!window.TCEForms) {
        window.TCEForms = {};
    }

    /**
     * Class for JS handling of suggest fields in TCEforms.
     *
     * @author Daniel Siepmann <daniel.siepmann@typo3.com>
     */
    window.TCEForms.Wfp2Suggest = Class.create({
        objectId: '',
        suggestField: '',
        suggestResultList: '',
        minimumCharacters: 2,
        defaultValue: '',
        field: '',

        /**
         * Wrapper for script.aculo.us' Autocompleter functionality: Assigns a new autocompletion object to
         * the input field of a given Suggest selector.
         *
         * @param  string  objectId  The ID of the object to assign the completer to
         * @param  string  field     The field which is currently edited
         * @param  string  table     The table which is currently edited
         * @param  string  uid       The uid which is currently edited
         * @param  integer minimumCharacters the minimum characaters that is need to trigger the initial search
         * @param  array   items     The available items
         *
         * @author Daniel Siepmann <daniel.siepmann@typo3.com>
         */
        initialize: function(objectId, field, table, uid, minimumCharacters, items) {
            this.field = field;
            this.table = table;
            this.uid = uid;
            this.objectId = objectId;
            this.suggestField = objectId + 'Suggest';
            this.suggestResultList = objectId + 'SuggestChoices';
            this.items = items;

            var itemsForSuggest = [],
                i = 0;
            for (i = this.items.length - 1; i >= 0; i--) {
                itemsForSuggest[i] = this.items[i][0];
            }

            new Autocompleter.Local(
                this.suggestField,
                this.suggestResultList,
                itemsForSuggest,
                {
                    partialChars: minimumCharacters,
                    fullSearch: true,
                    updateElement: this.addElementToList.bind( this )
                }
            );

            $(this.suggestField).observe('focus', this.checkDefaultValue.bind(this));
            $(this.suggestField).observe('keydown', this.checkDefaultValue.bind(this));
        },

        /**
         * check for default value of the input field and set it to empty once somebody wants to type something in
         */
        checkDefaultValue: function() {
            if ($(this.suggestField).value === this.defaultValue) {
                $(this.suggestField).value = '';
            }
        },

        /**
         * Adds an element to the list of items in a group selector.
         *
         * @author Daniel Siepmann <daniel.siepmann@typo3.com>
         * @param  object  item  The item to add to the list (usually an li element)
         * @return void
         */
        addElementToList: function(item) {
            var formEl = 'data[' + this.table + '][' + this.uid + '][' + this.field + ']',
                value = '',
                i = 0;

            for (i = this.items.length - 1; i >= 0; i--) {
                if (this.items[i][0] !== item.innerText) {
                    continue;
                }
                value = this.items[i][1];
            }

            // Add item to selected items.
            setFormValueFromBrowseWin( formEl, value, item.innerText, item.innerText );
            // Trigger T3 Framework.
            TBE_EDITOR.fieldChanged(this.table, this.uid, this.field, formEl);
            // Reset suggest field value.
            $(this.suggestField).value = this.defaultValue;
        }
    });

})( window, document );

Patch set 2 for branch master of project Packages/TYPO3.CMS has been pushed to the review server.
It is available at http://review.typo3.org/29769