Difference between each of those processors is less than 10%, wouldn't notice much of a difference unless your going to do a ton of rendering.
I personally wouldn't invest in a crossfire set up either. Unless 3ds max/ maya has changed dramatically in the last 2 years, all the video card does is render your work scene. I've been able to run max 2009 on a HD3300 IGP without any problems while working on individual models of around 5,000 poly. So unless your going to work with huge texture sizes, or extremely complex models, one dedicated graphics card should be plenty.