For YOU, i would get BFG AT KO...and stay away from deep mud. BFG AT KO gives you a decent ride on the highway, but has 3-ply sidewall protection. And in your size, it comes in Load Range C, which is perfect IMO in terms of tire weight (thus, handling, braking, & fuel economy), ride comfort, and durability.
My second choice for YOUR purposes is the new Goodyear Wrangler SilentArmor. The sidewall (called "Durawall") is good enough, not as strong as BFG AT KO, but stronger than other AT sidewall (e.g. Bridgestone REVO, Nittos, Yokohama).
I can tell you for sure that BFG AT KO's sidewall is thicker than Nitto's...i checked it out myself.
In my experience with many AT tires (e.g. BFG AT KO, REVOs, Nittos, Michelin AT), all of them have the same amount of tire noise on the highway. They are a tad noisier than your stock OEM tires, but definitely not something that your average passenger will notice. Nittos do have a "whine" to them on the highway.
In 265/70/17 size, some 4th gen 4runner owners have experienced slight rubbing, while others deny it. I have no clue who's right, but i doubt that the rubbing is detrimental to the 4runner.
Since you're upsizing, you will notice a slight decrease in power/responsiveness on the highway, esp. when cruising up a hill. The transmission may downshift more often, again esp. on hills. These effects should be minor (probably not noticeable unless you're anal like i am) unless you live in a hilly city/state.
Fuel economy obviously will decrease 1-2 mpg due to larger tire, more tire weight, and more resistance in the tread of an AT tire.
Nothing in life is free.

You gain in traction...you suffer in other areas.
I would upsize the tire and see if it's enough to make you happy. Other than that, you will have to get a suspension lift if you want more clearance.
Hope this helps.
P.S.: you can search for the tires mentioned above and see all the discussions & heated debates.
P.S. #2: I am going with Firestone Destination M/T tomorrow. It is supposed to be one of the most civilized MT tire on the market while still have amazing off-road traction.