Are you going to be stepping up tire size? If not, 5.25 " of lift is probably overkill. A good set of 2-2.5" springs plus a body lift or just a 3" spring lift would probably suffice for 33's. The more lift the lower you'll have to drop the T-case, becoming more of a "shovel" and really dropped T-cases are just plain unsightly. And other issues will arise, such as control arms being too short, so figure on replacing those if the RC kit doesn't include them. An adjustable track bar vs. brackets is never a bad idea, and you may as well replace the back one while you're at it. And as far as I've heard, a dropped pitman arm wont be nessisary under or around 4" of lift, esp. with an adjustable trackbar. I'd say just lift it enough to clear the tires you plan on running, and evolve from there down the road.
ok so no drop pitman arm and the reason for the BL is not to clear my 33's, i know the 4in lift will do that just fine, i just think a 5.25 in lift looks good.
But whats the odds ill need a rear adjustable track bar too? cause the kit comes with relocator brackets or something like that for the front and rear, but i wont need them in the front with the ADJ. track bar