6GB DDR3 ram on AM3 Board?

Hey, I currently have 2GB of DDR2 400mhz ram and suffer alot when working with motion graphics in my programs, I'm building a new computer soon and wanting to go either 6GB or 8GB DDR3 1333mhz, but since my heatsink will be blocking one of the ram slots it's forcing me to go either 4GB or 6GB, I'm just wondering if 6GB DDR3 1333mhz is possible to do on AM3 motherboards, and how would I go about adding them all? 3 in unganged mode? I heard there were issues with ganged mode with AM3 processors and DDR3 ram so that's why I'm choosing unganged. I work in programs such as: After Effects, Adobe Premier, will I be losing any big benefits going unganged over ganged?


Here's my Mobo I'll be getting:
Gigabyte UD4P

and my processor:
Phenom II 720BE
Also should I just buy a 2x 3GB set (the ones for intel supposedly), or would it be ok to buy a 2x 2GB and a 1x 2GB seperate.