All DFI NF4 Lanparty series of motherboards support Opterons as far as I know. The Ultra-D, SLI-D, SLI-DR, and the SLI Expert all support Opterons, most s939 motherboards support Opterons. Either the Opty 165 or the 3800+ will work fine. At stock the 3800+ plays single threaded games fine and plays great on multiple-threaded games. In AMD cores the 2 x 1mb cache doesn't help all that much over 2 x 512kb in games.