There are several boards that have an onboard RAID controller that will allow you to connect up to 8 IDE devices. ABIT makes some boards that might work for you, but there are also other board manufacturers that would be just as good. ASUS makes good boards too. Check some hardware review sites (
http://www.anandtech.com and
http://www.hardocp.com are 2 sites I read) and see what they think about various boards and chipsets.
There's also been some recommendations for the latest nvidia motherboard chipset so look at those too.
FWIW, I have an ABIT KR7A-RAID with an Athlon 1.4 and DDR SDRAM, and I use the raid controller for a raid-0 array. I have a cdrom, CD-RW, the 2 RAID hard drives, and a backup hard drive. It all works just fine for me. Make sure you have at least a 300 watt power supply...