I SSD boot drives in Raid 1 for the OS. Both raids need to be "hot swap-able" so that there is no downtime. I'm planning on using a Super Micros system with Windows Server 2008.
Supermicro makes a number of excellent boards. Good choice. Great NIC's.
I'm puzzled why you would want SSD in RAID 1. Theoretically it's fine, but it seems expensive. Aren't the error rates on the SSD's a magnitute better than mechanical drives?
As GhislainG has said, I also suggest a dedicated hardware RAID controller for RAID 5 to do all of the parity calculatons and provide onboard cache for the writes. His other points are also very important to consider.
My main home server includes dual power supplies (hot swappable) and a large UPS, RAID 5 for data, plus RAID 1 for the Server 2008 system disks. Difference is my system disks are WD Black label drives not SSD's. Cheap and reliable, and a five year warranty. The speed I have is fine, although I'm not running MS-Exchange or SQL that would add more disk IO and maybe slow things down. Certainly your setup will offer more performance but I wonder if it is the best place to make performance increases... better in a dedicated RAID 5 controller maybe?