Hard to say, Brian.. the stock FJ packs are what, 7 or so, right? I've seen a lift pack with 3.. rode like ASS.
Could you get by with a 2.5" lift? I had 35x14.5 boggers on 15x10, 3.75" BS wheels with a s.5" lift and con-fer shackles a while back and I don't remember any rubbing.. the rear fenders were trimmed up, and it still had front fenders. How big of a tire are you wanting to run?
Having had both the SUA lift and then SOA, I would go SOA as long as you want 35"+ tires, BUT.. instead of spending money on a lift kit, I'd do the following: Get 4 monotube shocks (Bilstein, Edelbrock IAS, NONE of that Rancho/doetsch/Pro comp cellular twin-tube crap), and a sway bar.
It'll ride much nicer, not soft and mushy, but taut. Most importantly, it'll be in control. body roll will be much reduced, while not beating you to death, and if you're going for something you're willing to drive hundreds of miles, a kidney belt shouldn't be required. Think BMW vs. lincoln.
Most SOA horor stories (mine included) come from reallly soft shocks, most often angled WAY in. Well, when you couple a soft spring rate with a soft spring valving, you get something that'll scrape the sliders going around a curve. But like on my buggy now, a soft spring rate coupled with the proper (firmer) valving in a QUALITY shock lets you get the control you need without being punishing. There's a HUGE difference between stiff (Rancho 9000 on "9") and firm (monotube shock).