As Naples said, a SATA drive won't offer much of a performance benefit unless you get one of the 10,000 RPM Raptor drives. There are some new motherboards starting to come out though that have SATA built in and connected directly to the main controller chips on the motherboard. This allows the SATA connection to bypass the PCI bus and theoretically achieve 150MB/s. However, until these new motherboards become common, you won't notice any performance increase using SATA drives.
I have a Seagate SATA drive and it has been working fine for me. It only cost about $30(CDN) more than the IDE version. the cables are much easier to work though.
goates