If you're interested in taiko, check out
Kodo (and their
smaller odaiko trio). I live in Okinawa, so I get to see a lot of drumming because of the traditional Eisa dances here.
Not sure if it'd fit with any of the civilizations, but tabla is a pretty well-suited drum instrument, too.
Curandero is probably my favorite group of all time. Aside from the fact that the musicians are possibly the most talented in the world in their field, I'm also a bass player, and Kai Eckhardt plays a fretless, and very well at that.
There seems to be two main styles of playing tabla, the
Aloke Dutta style, considered a little more modern, and the
Zakir Hussain style. Aloke Dutta is performing in Alex Gray's Chapel of Sacred Mirrors because he was the instructor for Danny Cary, Tool's drummer; Alex Gray does the artwork for their albums.
And I bet no one would think the
clay pot is an awesome instrument.
For the battles especially I tend to prefer percussive music. It's also kind of in line with the concepts at work in the game. Look at Holst's Mars, Bringer of War, and compare it to the rest of the Planets series--people naturally associate battle with percussion. I used to be an active musician, so I relish any chance to discuss and share it!