I'm buying an iMac so I can do my work at home. So.. I can't figure out whether I should get the Imac 20'' with ATI Radeon HD 2400 or the ATI Radeon HD 2600 and connect an additional 24'' monitor? Or if I should take it up a notch and get the newest imac 24'' with the NVIDIA GeForce 8800 GS card? Does the NVIDIA GeForce 8800 GS card make a difference for editing? I'm gonna use it for gaming or 3-D. just editing and colorgrading. And no matter what option I'm getting 4 Gb of ram.