So if most of you believe GSP stands no chance against Silva, Silva has to move up or someone has to move down because GSP is the best in his division and if you don't think GSP can beat Silva, no other welterweight is going to imo. GSP already looks about the same size as Silva at 15lbs less and he's really long.
So yeah... if you guys are ruling out GSP, you may as well rule out the entire welterweight division. I would also rule out almost all of the heavyweights so that leaves the light heavyweights because I don't think Silva can put on 40lbs of muscle to match most of the heavyweights. Even if he put on 40lbs of muscle to get to 225, he'd still be way smaller than the top heavyweights. JDS(240), Cain(240), Fabricio(245), Carwin(255), Overeem(260), Mir(260), Lesnar(265). And a lot of those guys are great at take downs/former college wrestlers. If Chael can take Silva down, so can they and they have waaaaaaaaaaaay more power to finish.
The only bigs I might be interested to see him fight are Fabricio, Big Nog and Roy Nelson. And that's only because he could get close to their weights without it being completely lopsided. Even though Cain and JDS are the smallest of the best heavyweights, I think they're too good for their size for Silva to put on 40lbs and immediately step into the ring with them. Cain a former wrestler would take Silva down and JDS is just good.
I would rule out Jon Jones because again, he can take down Silva just like Sonnen did only he'd finish Silva after he gets him down. So it should be down to basically anyone in the light heavyweight division except Bones imo. Rashad Evans, Dan Henderson(II), Lyota Machida, Shogun Rua, Phil Davis, Alexander Gustafsson.... one of those guys or GSP is the fight I'd go with.