It seems that a list like this would be very helpful to the community, but there are many issues with trying to keep a spread sheet to do it.
I have a proposal for the mod creators - please let me know if this interests you.
I think it would be better if the "complete list of mods" could be updated by the mod owners using xml files that they control. They can automate the creation of such files - then I could pull the xml data from them and create a current, accurate list automatically.
Here is a proof of concept. There are links at the top to samples of the format of the XML data. It seems it might not be too hard to automate the collection of this data from your existing databases if we keep it simple.
Once this data is pulled together - there are many possibilities like adding searches and sorts that would direct the XCART community more quickly to your products.
There is also the additional possibility of later adding rating and review systems so the community can participate.
There is also the possibility of adding listings for other services - like design or programming.
One advantage is that the generation of this list depends on the active participation of the module creators. If they disappear or stop supporting, they can be dropped from the list. Addition of customer support rating and reviews could also curb some of the abuse that is being reported on the forum.
If the the module authors are interested in participating in this - please let me know. I'd like to work with you to define the data and the XML format, and get this list active.
Also comment if you see problems with implementing this - or know a better way.