Case solution (Score 3, Informative)

We built some disk arrays using a front-loading IDE case with drive trays. This one is pretty pricey but it's _nice_ hardware:

https://www.rackmountplus.com/spec.asp?ID=RMAC4D -IDE

That, plus a couple RAID cards (like 3ware's new 12-port cards) in a 64/66 PCI slot and bonnie++ would do a pretty good job of burning in your drives. You could flip drives in and out in a few seconds.