New Computer! HELP!!!

Hey guys, I have a situation in which I need some advice. I am buying a new computer and I have narrowed it down to two choices. Basically the computers both have 8 gig's of ram and a TB hard drive. The source of the confusion is in the processor and GPU. In choice a I could have a Amd Phenom X4 9750 Quad Core 2.4 Ghz with a Ati Radeon 4870hd. Or I could go with choice b, which is fifty bucks cheaper, and have a AMD Phenom II X4 910 quad-core processor (2.6 Ghz) but with only the Radeon 4850. I want to play graphically intensive games such as Crysis on the highest settings possible at high resolutions. Which computer should I go with? Thanks!