I'm running an epic fantasy soon, and I'm using Burning Wheel to do it, but I need to amend the magic section. In this world, there's no such thing as "mages" and "civilians." Everyone can use magic if they have the training, because magic is just bargains with various spirit forces. The problem is, I don't know how to represent this mechanically. I read about GURPS Thaumatology, and how it has some alternate magic systems that might be useful, but I haven't been able to find it.

tl;dr - Upload GURPS Thaumatology and give me ideas for bargain magic.