4mm tape drive fir a server?

[jaylee11]

I have a friend who is building a server for someone, this is his first shot at building a server. He is planning on using the asus dual proccessor board and 2 xp1700's. My question is what kind of tape drive should he use? He is wanting to use a 4mm tape drive for backup purposes. He is looking at one that is atapi, because of the cost. Most of the drives are scsi but are way more expensive. He is planning on an 80 gig hard drive. Should the tape drive be the same size as the hard drive? This is something that is brand new to both of us. Any and all information would be welcome and greatly appreciated. Thank you.