I did a prototype of one in 2D.
With DBP going on, I'm not going to reveal any particular secrets, but trust me, it's highly possible.
check this. 3d fighting game.
http://www.youtube.com/watch?v=elhBygNg9AA&feature=related
Bo Ryder Mitchell:Ive seen one dude but I cant ask what kit he used so if any of you know that then tell me please
There are no starter kits for fighting games. I would bet that all those games are coded from scratch just using XNA Framework.