Newbie here, but a little experience in sort of the same thing you're thinking about. I turbo'd a car I used to have, that didn't come with a turbo. Putting a turbo on a non-turbo motor is a lot of work. Besides the turbo you have in your hand, you will need (off the top of my head):
1. Turbo exhaust manifold
2. Fuel Pressure Regulator
3. Piping
4. Oil feed line
5. Oil drain line
6. Oil drain fitting at the pan
7. Coolant line (if the turbo runs on coolant also)
6. Coolant drain line
8. Down pipe
9. Bypass valve
It's a lot of work for not that much in reliable horsepower gain. The higher the mileage on the motor, the more likely you'll start breaking stuff. Boost will likely be limited to about 5-6psi to remain reliable. That means you'll likely have to re-spring the wastegate for lower boost also. Most turbo motors will use about 8+ psi because they're built with lower compression and stronger parts for the higher boost pressures.
I'm new to the 4x4 stuff, but in the best case scenario, your 4Runner motor is a derivative of a motor that came with a turbo (22R series of motors had the 22RTE). If you can find and get all the hoses, fittings, etc., that would make the swap a lot easier, but at the end of the day, adding a turbo to a non-turbo motor just isn't all its cracked up to be. My experience comes from here:
Project X
I think ultimately, it's better to take the time and money you would spend on adding the turbo, and putting it into something else, like a motor swap of some sort if you're looking for more power, or other parts.
Good luck.