Don't forget about the difference in the bumper heights. I don't know what you're running now, but for some of them, they just don't work well with a body lift.
Now, after saying that, i have the RRO 2" body lift. I wish the spacers were wider though to put better leverage on the bushes, since they're 3" or something in diameter, and the spacers are only about 2" (all from memory measurements).
The kit was very easy to install though, with the exception that i needed longer bolts in the front most body mounts than were supplied in the kit.
I heard the masterkit1 3" BL was pretty good.