you would need a server motherboard
asus kgpe-16
I tried to order those 6272's a few months back and ncix couldn't get them for me.
Also, the bulldozer opterons (6200's) are no great hell, magny-cours (6100's) are still the way to go.
And, You would probably need to pickup a 6128 chip in order to flash your board's bios so it could accept 6200 series opterons too. (AFAIK it won't come with the latest bios that has 6200 chip supprt).
as previously noted, it would be best to just pickup some 6168's or 6174's whatever your budget can handle.