It's true that a Chevy chassis is not the strongest (open frame), Toyota have stronger chassis (boxed frame), but IMO, a full frame will have stronger suspension mounting points than a unibody.
I remember my days of 4wheeling, the Cherokees were twisting a lot.

On the E46 BMWs (325i and 330i with 184-230hp), the subframe is tearing the floor apart under spirited driving. Since you're planning to have 1000hp I would check carefully the mounting points of the subframe, and may be reinforce them.

Well I think I found the truck... It actually looks identical to the truck in your sig... :)

Let the planning begin :)

Airbag suspension will suck, and I hope you're not thinking you can control axle tramp/wheel hop with a stiffer swaybar, that will only allow it to transmit torsionally to the other wheel. 1000 hp will require stiff, extreme progressive rate coilovers for street use!