I'm thinking a shop like this could also make it very easy for us to "package," save, and preview whole sets for use in a later movie.
I envision a "shop" much like an online store, where links to the various categories are listed across the top with subcategories and other special functions listed down the side - maybe even a link to the online store so we can download content from right within the game. I don't know what it is - probably too much online shopping otherwise - but I just really like previewing items in a full screen mode. Also, my picky self says scrolling left to right feels unnatural; I like going horizontally.

Mostly, I'd really like the ability to look at large pictures of the items, turn them around (360 view, that is), and even scroll my mouse over color and condition (old, new, dirty, etc.) options to see what they'd look like. There could even be a blank box for us to upload our own custom colors/textures to and then preview and select right there, rather than doing it all in the mod shop (if this is even possible).
I know implementing this idea would probably take a lot of work. Maybe this is even a ridiculous and superfluous idea. Any thoughts?