Grubbworm

I am researching motherboards for a new build. I am considering an AMD cpu, possibly a 64x2 5400 Black Edition. With an eye toward the future and an upgrade to x4. This computer will be used for a variety of things; i.e., web surfing, gaming, media/graphics, and some software beta testing among other things. I would like to run Vista Ultimate 64 on this machine, or maybe I should say multiple operating systems. I am also trying to work within a minimalist budget, and would like to keep the price around $100 or less for each part. I already have a RaidMax Smilodon ATX-612WBP case with a 500w power supply. Right now I am looking at a DFI LANPARTY JR 790GX-M2RS or Gigabyte MA790GP-DS4H Motherboard. But, I would entertain any and all suggestions. also, if links to reviews were included that would be nice. Thanks in advance for any and all help.