if your hard disk is ata133 you need an ata133 controller card. a ATA66 will not do, your 200 or 250GB drive is at least ata100 if not ata133.
i assume by your lack of knowledge as to what kind of interface your disk is , it most likely is ATA100 or ATA133 EIDE.
as for where to get them, might want to actually read the link i gave you..... its not that hard if you just try.......