Today we were hoping to get our doors installed, but the local home improvement retailers didn't have the styles that we want in stock.  We placed an order for four doors and they should arrive in 2-4 weeks.  The really nice part about it is that we were able to order a custom-sized door to fit the "soundproof" wall for the studio.  The door jamb size for that wall isn't a typical size because of the two layers of 5/8" drywall on both sides.  We were able to order a jamb size to fit, plus a threshold at a custom size too.  We were concerned at first because we thought we were going to need to mess around with a standard-sized door in order to get it to fit - we just assumed a custom door would cost too much.  It turns out it wasn't much more expensive than a standard size.