I'm considering purchasing the same processor, so I'll share what I'm looking at for motherboard and memory.
I'm getting one of the ASRock K10N78M AM3/AM2+/AM2 NVIDIA GeForce 8100 Micro ATX AMD Motherboards and one of the G.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 1066 (PC2 8500) Dual Channel Kits.