What Boxcar said. There are a couple of SJ's running around with full Toyota running gear under them, which I feel is the way to go if your going to swap in the 22RE. That way you get the ability to chain your transfer cases together, but still keep the smaller vehicle.
Instead of the 22RE if you need more power then the 1.6l I would look into a 2.0L/2.3L conversion from a newer Tracker or Suzuki Areo. Even the 1.8l is a nice swap. You keep the light weight and can bolt them up to the stock transmission or use a 2wd transmission from a Tracker/Sidekick. ewbewley had a 1.8l with computer/wiring and a 2wd transmission a few months ago and could probably hook you up.