Go Iwill! I built a system for a friend at work with the non-RAID version (he's a SCSI freak). It's a really well made board that setup real easy. It's certainly got all the features, just like the Abit, but I don't trust Abits quality and their support is non-existent except for far too many BIOS fixes.
I have both Abit KT7-Raid and Abit KT7A-Raid. I personaly like the KT7A-Raid a whole lot better. Don't know any thing about the K266 board. As long as I have the luck I have Had with Abit I won't switch.