This is a good question and one that needs some response by koto.
Would koto do a Hulk from a not-so-modern story line? Most of there stuff seems to be more current? Would they go back to the 70's for a Buscema sculpt? Would they go to the 90's for a Keown?
Erik's comment makes me wonder if they are going to branch out and do non comic book based Hulks - meaning not based upon a specific reference.
My thoughts on Sal - not sure if koto is looking to do the old school stuff. To be honest, I am not sure if a more accurate comic representation of Sal can be done on par with Troy's Hulk. Not that I would not like to see it tried though.
Now that the perfect 3D Sal Hulk is being done (Troy), my vote would go to Keown's smart/professor Hulk. I have been banging this drum for a LOOOONG time and have compiled a few really good shots of what I would like to see (when I was close to having one done myself) ... black wifebeater and packed to the nines in mega guns!