I will say this about GURPS though, 4th Edition is a significant step up in most respects. I recently picked up Martial Arts 4th Ed and am itching to start an anime-styled martial arts campaign, but I don't think that my group of players is really into that enough to make it work, save for maybe one or two. Combined with GURPS Powers it's pretty easy to do, of course there's always BESM, but I've never played it though and don't know if it's worth the effort of learning another system.