I would call a few commercial supply houses.
Raco makes a 2 gang 1" deep box
Part number 418
http://www.hubbellcatalog.com/raco/r...325,11469,9118
Here are 1 5/8" deep boxes. They are made by ThePitt who was bought out by Cooper.
http://www.foxelectricsupply.com/con...uctNo=CRHTP629
http://www.foxelectricsupply.com/con...uctNo=CRHTP631