akai s2000 hard disk scsi requirements

[tj jr.]

i want to get a hard drive for my s2000 and i dont know the requiremets. How many pins does it need to have? I see scsi drives go on ebay cheap and i want to get one but dont know if it will work with my s2000. I was gonna get a 540 meg drive.can i get any drive as long as its scsi? help please.
thanx in advance
tj