Hello,
The list is a good idea and something we will look into making in the future or combining into the Compatibility List. For now I would suggest using this page here which groups every extension / template into folders.
http://www.shape5.com/component/option,com_docman/Itemid,96/If you have any questions about where to find something feel free to let us know. You can also look at the Topics in each Forum to see which Extensions are Paid vs Free.