I'm developing a cms that allows editing everything on the page (generated server-side with a template engine) by just clicking on it — the area turns into input field, textarea or a full-featured tinyMCE editor, Template defines editable elements like "page heading", "copyright footer text", "image", "rich text block" etc.

Along with that there's always a flotaing panel with several tabs, some of which contain general settings like page bacground color, font settings etc, but some are context sensitive (e.g., the clicking on "image" editable field triggers to display uploading/cropping/captioning interface in the floating panel).

All settings in the panel are either simple inputs or sliders or checkboxes.

I'm new to using MVC with javascript, and in fact haven't used it much before. jQuery is used as code library for the project. Should i use JavascriptMVC, SproutCore or anything else?

Does any of them allow some kind of sandboxing (within bounds of commmon sense) to allow some javascript code by user-generated skins on my cms?

thank you!