Wow. The Sabertooth model is all fancy-nancy with it's "TUF thermal armor" and "TUF thermal radar" and "TUF components." I really think Asus wants you to know that the Sabertooth P67 is one T-U-F motherboard.
I don't recall seeing a main board with thermal housing before. I know if it were me I'd be wanting to find out if someone else has used this before and how well it worked.
I think you've specced out a pretty good power build here, D3. I'm just curious why you want two 750 GB HDD's as opposed to one 1.5 TB drive. Are you going to put them into a RAID 0 or RAID 1 array?