You should check out the Gigabyte K8NS Ultra-939 too.
That supports dual core with the F7 or higher bios. Also I had no problems with getting all the onboard (audio, dual GB-LAN, firewire, etc) running with 2.6.8+ kernels. It's AGP as well. I wasn't ready to give up my 6800GT yet
I just checked out the cpu support list for that A8V Deluxe.
It supports dual cores (in bios 1013 and 1014).