I had 2" ir shocks on my tacoma, but mine was a 4cyl, I assume yours is a 6cyl. The 2" shocks (racerunner) seemed to handle it fine not sure the pressure I had in them but I think it was ~275-300PSI, probably a little higher than most run them. It handled good on and off-road, just make sure to get GOOD shocks for the rear. I had Bilsteins in the rear and they were GREAT, put superlift softride's in the rear before I sold the truck and they rode like crap.
My Tacoma had a full cage, front bumper, custom built frame front and rear, so I feel for sure the front was as heavy if not heavier than a stock V6 truck front. Although I had no problems with the 2" shocks (or complaints), you might be better with a bigger air shock, that way if you add bumper/cage/winch you will be good to go.