Build or customize a control like Chosen with multiselect, ordering, searching and deleting from local data and JSON

I have a customized Chosen control, allowing to select multiple items from a long list of items, grouped by category. Once selected, their order can be rearranged or items can be deselected pressing on the garbage can icon. A search box is available, allowing fast search for the looked element. The search needs to be started after few seconds (customizable) after having entered the text, so to avoid the search for "1" when entering "100". The current implementation relies on local storage, the new implementation needs to be able to use both local storage and JSON sources for retrieving additional elements or performing searches. In details, two JSON scripts will be available, one returning X elements for the selected category, the other returning X elements from any category based on the search term. At the end of each category, a new "More..." item must be shown, allowing to download X additional elements providing a start position and the name of the category. Multiple Chosen controls can be used in the same page working with different data. The way selected elements are submitted needs to be not altered, to make it easier to replace the control in the application pages. Multiple instance of the same item needs to be able to be selected and ordered. The look and feel of the element needs to be maintained. The control needs to work inside the responsive template "Smartadmin", working with normal browsers and mobile phones. At least Chrome, Mozilla and Internet Explorer (old and new version) needs to be fully supported. Full source and unlimited right to use will be transferred to me. Access to a working implementation of the current Chosen control will be granted. It needs to work with the new implementation. Asking for partial payment for partial work will be not granted.