EXT64
Splendid
The AM3's have already been tested by Gigabyte (check their website) so they have at least a few made in retail (C2) stepping.
One word of caution, I have the Gigabyte board and it still has a few minor BIOS glitches. I can tell you them if you'd like. From what I've heard, the Asus 790GX is a little more stable, but accounts vary. I'd suggest sticking with the 790GX since it is very good for the price.
Also, if you are worried about the shipped BIOS being incompatible, just buy a cheap $20 Sempron for that first boot. On top of it, at the time I bought mine my board was $10 off so the extra CPU cost only $10. Not a bad deal if you ask me.
One word of caution, I have the Gigabyte board and it still has a few minor BIOS glitches. I can tell you them if you'd like. From what I've heard, the Asus 790GX is a little more stable, but accounts vary. I'd suggest sticking with the 790GX since it is very good for the price.
Also, if you are worried about the shipped BIOS being incompatible, just buy a cheap $20 Sempron for that first boot. On top of it, at the time I bought mine my board was $10 off so the extra CPU cost only $10. Not a bad deal if you ask me.