decisions decisions...heheh

you can get any of several 2-port PCI SATA RAID card for under $70 (look for another thread here, I wrote a mini-review of the Adaptec 1210SA)
...but 4-port cards start around $200 and are usually $300+
Here's a product you might consider:
Promise FastTrak S150 TX2 Plus...it has 2 SATA and one PATA (aka "IDE") channel...and like all the Promise
cards, can support two arrays. This puppy is a sweet deal...NewEgg for instance lists 4 skus for it, ranging from $40 to $72.
Hmm, it seems I'm slightly out of touch. They also list Promise's S150TX4 for $117 - also an excellent deal...
If you want top performance, look for a controller that supports NCQ/TCQ; tomshardware.com recently did a writeup on this technology.