I'd suggest something similar to that which the vBulletin forum software uses. Not sure how much you can see without having to register but it's at :
The forums are set up for different versions, themes and plug-ins. The allow you to tag ones you're interested in and also keep track of which ones you've downloaded to use (and they prompt you to mark them that they've been installed). As well as all this there's a rating system plus how many downloads etc.
It's really useful and easy to use/navigate. If it could be adapted for Moodle use that would be great !