Looks pretty cool! My only comment would be to watch how those pony clamps twist your cabinet. They can really pull them out of square quickly, and even 1/16" on a cabinet holding a large amount of weight like this one will eventually cause problems. Do you have access to a case clamp? if you do, make sure you cut your backer perfect, put the cabinet into the clamp, and attach the backer. That way everything will be nice a square and you won't have to worry down the road.
Sorry if you already knew this, just trying to help, I look forward to seeing it done. What are you thinking for stain? IME oak looks awesome in a rosewood stain, as the grain goes nice a dark, and the rest stays fairly dark, but also has a nice red tint to it!
Pics soon please :P