With a detroit replacing the stock carrier and Alloy USA shafts would 39.5" Iroks be out of the question? 4500lbs'ish 350hp/375ftlb @ the crank. 4.56 gears.
Four Wheeler had made some comments on the axle a few months back, and they said that it could be possible to cut the ends off a 9" (plus axles) and use a "c-clip" eliminator set up, and it may also be possible to use 9" gears with some machine work...You shouldn't have much problem with the combination your looking at if your easy on the pedal. I would say the 9.25" would be very equal to a Dana 60 with 30 splines as far as strength goes.
The biggest problem with the 9.25 outside of it being a "c" clip axle is that there is just no aftermarket interest in them. There are really very few upgrade options available, but you shouldn't have much issue with what your looing to do.