How much is your budget for the motherboard? You should give this info in the first post itself for better replies.
As per as my understanding, motherboard and PSU are the two most crucial components of a PC.
I am also building a similar PC, a 965BE, Radeon 8670HD, Corsair 650W SMPS and 500GB HDD.
I have seen some motherboards (around $130-150 range) recommended by various friends as well as members at this forum. My budget is roughly $100-115 though it seems I'll have to make it higher:
1. Asus M5A97 EVO UEFI (This one has AM3+ socket, SATA3 6GB/s, USB3.0 etc)