If your M/B supports Sata then go for it, but if it does not then you will have to get a PCI interface card to use the SATA drives, this should not be a problem if the drive will only be used for storage, but if you intent to boot from this SATA drive then you will have to install the SATA drivers from a floppy when installing WinXP.
I have used both SATA and PATA drives and can't see a real speed hit, there obviously is because of the data transfer rates, but i have never felt the hit.
regards
succuba