Or use SATA if there are SATA slots available on your mobo, I know mine has, 2 IDE slots, and 2 SATA slots, so I can have in total 6 devices without controller cards.
But if you do buy a controller card you can choose out of SCSI, SATA and IDE, I would choose SATA if I were you. Costs maybe a bit more, but SATA is much faster and generally better, cause it's like IDE version 2
, also SCSI is mostly for high-end server systems.