Thanks Frank.
I ended up just going with a locations of arrangements/TexMEx/TexMex
If there was a way to checkout the whole texmex/ tree (of which texmex/TexMEx is the location of the thorn), that would be my preference, but I couldn't figure out how to get it to do that, and still have a usable ThornList for configuring Cactus. So people will just have to checkout the rest of the library manually.