Suge is one big ass dude but if you watch the Charlie Hustle movie, E-40 claims he can fight and he says somethin like he wouldnt lose a fight with anyone one on one. I have no reason to think he couldn't whoop some ass. Plus I've heard of several stories where 40 has stepped up to hella people.
But if I had to choose, i would say Suge. but I guarantee 40 wouldn't back down and would definitly get some good ass hits in.