I have a raid with two 80GB SATA Drives. One o the drives has completely failed. I am trying to?

I would think so. You might also have to reconfigure the RAID. You know for just a 80 gig hard drive if your looking for redundancy you could just use cloud backup, for just a couple bucks a year, and then your data will actually be safer, as you could restore it from virtually anywhere. But ya, to answer your question, you should stick with the same model.