If you have a 2wd, you can get the PRG 4" Spindle Pkg. and add any of the stock height application coilovers for 2" more lift. You will also need the CST carrier bearing drop bracket, (any rear lift > 2" on a 2wd requires them), and probably different, taller blocks than what comes with the pkg. Rear shocks come with the package and PRG sells different lengths, for at least very close to the same price.
There are three stock application coilovers to choose from, all of which will provide the last 2" to 2.5" of lift, on top of the 4" from the spindle. The least expensive is the Radflo 2" diameter body, then the new PRG spec 2.5" body Sway-A-Way, (SAW), and finally the 2.5" body Donahoe Racing, (DR or DRE), coilover. Any of these will dramatically improve your Titan's handling in stock or spindle lift applications.
The coilovers that come on the bracket lifts, (if provided), are said to be inferior. If you go the bracket route, you can get other models of the Radflo and SAW spec'd by PRG, (so buy the bracket lifts without coilovers, and upgrade them with some from PRG). I believe the bracket lifts have less ground clearance than the spindle lift, but I might be wrong ... and the differential clearance is determined by tire diameter.
To see the PRG 4" Spindle Package click on the link in my sig. It is the first pkg. (mine is the second pkg. but you can see a pic of the DR coilover in the second pkg.). I would get the SAW if I was buying today since it is spec'd and put together by PRG, although I love my DRs. Note: The SAW of the second pkg. requires aftermarket UCA, but the stock application one that I suggested for your application doesn't.
Not all of his products are shown on his website,
PRGproducts.com, but if you call him, he will build you up a package for your individual application ... bracket, 2wd spindle, or just shocks. Greg's number: 951.780.5331