Peyton Manning, hands down. This offense seems to cater to a pocket passer, not a scrambling QB. Not to say a scrambling QB such as Vick or McNair wouldn't be successful, but that a pocket QB such as Manning or Harrington would flourish in this system.
Manning is the best play-action QB in the NFL right now. Ricky is the best runningback in the NFL right now. Put those two together, and you have a very scary tandem for a defense.......