If you just want 31's crank the t-bars, but if you want bigger tires you can do a body lift with 33's. A BL is around $165.
I have cranked t-bars and 3.5" lift spindles in the front and 3" blocks, 2 sets of AAL's, and Chevy drop shackles in the rear. I am 2wd though. If you want a suspension lift for your 4wd you're gonna have to fork out the cash.