Hello. I have in my Mid 2010 Mac Pro the ATI Radeon HD 5770 1024 MB. What graphics card is out there that has better graphics and also supports 3 to 4 monitors easily? My budget is in the 300 to 400 range. I've seen the EVGA GeForce GTX 680 for Mac, which is amazing, but out of my budget. I need to get three monitors running soon.