Buy an unbuilt toyota. You have to consider the fact that the only aftermarket that youre going to be using from a built rig is the drivetrain. Basically, the optimal thing you could get would be dual cases w/ 4.7's already installed. you will have to CHOP those one tons down, if you wanna drive it on the street (obviously). i actually pondered buying those axles from you when you were parting out your truck. Personally, I like 1st gen runners for their style. But if you think about it, "built" usually involves a lot of work on the axles, especially in toyotas. Why pay 5 g's for a rig with dual cases, gears and lockers in axles you wont use, tires and wheels you wont use, and suspension that you might replace? all those aftermarket parts will just be a trouble to part out, too. The only common aftermarket thing you would use would be the dual cases, which would cost you just over 1000 bucks to build yourself. So the price of a built rig is somewhat pointless other than the drivetrain. As for springs, your unsprung weight will be significantly greater with your one tons, thus the springs will be stretched quite a bit more and droopier overall. That'll be sick, man. I'm looking forward to the build.
just my two pennies worth!
-Tyler