I did it. I bought the case from some company in California off eBay.
It came sealed in the original box from the factory in China. Had a complete set of new fans inside, too. Bluetooth and Airport antennas were included as well.
A very easy (and fun) job to swap the hardware into the new enclosure.
I recommend that the LAST thing you remove from the OLD case is the PSU. It's much easier to turn the hex screws with the motherboard out of the way. And, for the same reason, the PSU should be the FIRST thing you place into the new case.
Motherboard removal is a bit tricky. The Apple Service manual shows you how to disassmeble.