Antec Take 4 (studio series) might do the job for you

http://www.antec.com/us/productDetails.php?ProdID=94004

In my opinion the case makes less difference than the CPU fan.

If you buy a quiet cpu fan your box will be quieter.

Adding rubber groments under your hard drives will reduce some vibration transfer to the case too.

Case fans should be large and slow to reduce noise.

CD/DVD drives will almost always have noise when there motors are running.

Adding a fanless video card, helps elminate one more noise source.

Adding sound foam insulation is a BAD idea, it helps trap heat in the PC and cooks your CPU faster.

Rack mount case IS *KING HEAVY! REALLY *KING HEAVY. I bought one and then decided it would be easier to connect delta 1010 cable every time than carry that sob. Just get a mini ATX case with handle on top.