Lashley or Henry.
Im going Lashley for the speed and being ex military, If lashley uses his head, he would just run around a bit, ducking slow punches, make the big man tired and the njust smash the crap out of him.
Chris Masters or Taker
Taker, mainly on experiance, Taker could destroy Masters, Masters wouldn't even have a chance because of the roid taking.
Batista or Cena
Batista mainley again on the Bouncer experience, It would be close but Batista would know what to do even if he got the crap beaten out of by Booker.
Khali or HHH
I have no idea why everyone is saying Khali? In a David Gholiath fight its usally David coming out on top, HHH has experience and would just duck Khalis punches, take out the big mans knee and just piledrive punches into him.