The number of onboard SATA ports depends on the motherboard and the chipset(s) it has. If it doesn't have enough ports, you can add a controller card and most cards will support RAID at various levels. If the SATA ports support RAID, it doesn't meant they have to be setup in a RAID array. The best thing is to find hardware that supports win2k3 and has the features/ports you want, don't sweat if it's RAID or not.

Hope that helps...