Let me save you some time and trouble, as a guy with a really nice 5.5 ft bed crewmax who now regrets it...
Get a Chevy 2500 short bed crew cab with the 6.0 vortec. I'm a Toyota guy through and through, but my neighbor got this truck for a solid 10k less than I paid and I should have done the same.
From what I hear, the 6.0 vortec is a reliable motor even though it's not a Toyota 5.7 which is quickly becoming legendary.
Also, if you're anal about payload, read the owner's manual for the tundra. There are some shocking surprises in there that I don't see much mention of online.
I will say that after hauling 3000 lbs of gravel that I have no doubt the tundras are conservatively rated, but still... I like to stay within spec if I can, and there's essentially no way to do that with any FWC shell and the crewmax.
The double cab could probably work with a hawk (in terms of adhering to the owner's manual), but it depends on configuration. Of course it "works" in general, as I'm sure many here can attest.
I've owned a double cab in the past and they have plenty of rear seat room. The Chevy has a bit more with the same size bed, much higher payload, and a much lower price.
I'll personally still probably try to make a Raven shell work in my crewmax, but if I had the truck to buy over again, I'd spend the same money, grudgingly, on a 1-ton, SRW, and not have to think twice about payload.