Hmmm...
Would be interesting to watch him upgrade, ummm, the 2nd CPU from the bottom?
Nice do it yourself rackmount, or is that stackmount?
You could probably do this with almost any system, just have to make sure the MB mounting holes all align up. In that case, you wouldnt need to have them all the same MB's.
I was already looking over my ATX cases, and thinking about laying them on thier sides, and make an ATX "case-rack" for them.
Now, if I could just afford to buy 7 of those 8KHA+'s, and 7 XP1800's.....