First, every 4Runner is a bit different when it comes to it's response to lifts, so YMMV. That said, it really goes back to your goals. Do you want the lift to: allow you to run larger tires, too improve approach/departure angles (that was my reason for lifting), firming up the ride (another goal), increasing ground clearance for the front skid in KDSS-equipped Trail Editions (my final goal), or to look better as your perceive it? (yes, I wanted a "better look").
That said, it seems as if you want a lift without replacing the OEM UCA's. So, that means you are limited to lifting the front <= 2", and how much you lift the back is dependent upon whether or want to maintain or minimize the factory rake.
Be advised that the published lift rates for rear coils do vary a bit from the real lift. Also, the higher the lift up front, the less likely you will be able to get your front caster in spec (that's why new adjustable UCA's are needed for bigger lifts, to get the castor within specs). That said, "many" here report adequate front castor (but not necessarily within "spec") with <= 2" lift. So it's a bit of a crap shoot. BTW, you don't really need a lift to run 275 tires as the lift doesn't really affect rubbing up through 285's = rubbing issues can solved in other ways.
For me, I met my goals with an alignment that worked for me without the need for new UCA which I wanted to avoid (I have a limited budget). If you like the rake, the 6112's set for 2" lift and rear 2" Icon lift springs paired with 5100's should work. If you want to minimize the rake while maintaining the 2" front lift, then either a 1" spacer or a 1.5" rear lift spring would be your route.
All that said, I researched this forum and others thoroughly over time, honestly thought about what I wanted my lift to achieve, and I'm happy to report I'm happy with the result one year later and have no plans to change. I run 275 tires in the summer and 265's in the winter. I had some minor rubbing with the 275's which I solved with the front fender liner mod.
Good luck!
http://www.toyota-4runner.org/5th-gen-t4rs/92594-modifications-write-ups-quick-links-faqs.html