One thing that most people don't think of while hosting a wordpress theme-site is that the people visiting the website often wants a search function. Try to implement that!
I use -Wordpress Download Manager for managing downloads -Wordpress Theme Demo Bar for showcasing themes
You shouldn't have too much problem finding the correct theme/plugins. If you see any Wordpress gallieries right click and view source to see what plugins their using.
That doesn't always work. Some plugins do not "show" that they're plugins in the source code. One plugin that actually "shows" that it's a plugin is the all in one SEO pack. No more plugins do that. Kind of.