[Brad54]

That bed is pretty cool! I think that'd look a LOT better than a wood bed.
You'll want power brakes and a dual reservoir master cylinder. That's a lot of weight to stop with no assist.

I know you've got your heart set on the 454, but you might consider a simple crate 350. It's a lot cheaper to get everything else you'll need to install it in your truck (exhaust manifolds, carb, pulleys, brackets, etc), and its factory, so you won't have to worry about motor mounts, exhaust routing, modifying the fan shroud, firewall clearance, etc etc.
I don't know what a stock 454 makes for power, but there are a gazillion options available for crate small blocks. And many of them are VERY inexpensive.
Keep us posted on the truck!! (Especially that bed!)