Wondering if this is possible?

So I'm wanting to have a feature kind of like the upload media button but for pre-made content.

I have a multi-site setup and I want my users to be able to pretty much pick slides out of a drop down or library?

I have seen the file manager plugin which seems like it might work (but don't know if it would upload html), but was wondering if you might have any suggestions.

Thanks,

Chris