Rackmount cases generally have no PSU(s) as standard equipment. But you'll generally be looking at a 5U case to hold two full ATX PSUs. 4U cases can sometimes handle the compact redundant PSUs. OTOH, you may be able to figure a way to put two 1U or 2U PSUs into a 4U case. Good luck.
Also see my reply to the "IPC Suggestion" thread here.
.bh.