I'm in a similar position as you. Kid #1 is moving out of the "nursery" to make room for Kid #2, thus Kid #1 gets the guest/computer room so my desktop, etc. will be moved to the MBr or dining room.
I've looked at computer amoires a little bit. Most of the ones I've looked at are pretty roomy. There's usually dedicated space for a mid-tower, printer, monitor, keyboard/mouse and a fair amonut of shelving. The only odd ball periheral may be something like a scanner.
Although I'm not real keen on them, the one feature that will be a must if I do get one is fold away or retactable doors. The upper and lower doors are usually pretty big and if they don't fold away or retract, those 30" doors always seem to be in the way.