I think I might install the OS to 1 drive like you said. I'm not looking for fault tolerance as this is a desktop machine and I have reliable backups. I'm really just looking for a way to get away from the raid controller on the board. However I'm not really wanting to spend any more money on a separate raid controller as I'm going to be building a new machine in the next 3-6 months anyways.
I think I might install the OS to 1 drive like you said.
Just make sure you set the bios to ACHI first. The OS will install and run fine either way but will be very blue if you switch the controller type after install.