2JZ is a 3.0 liter straight six designed to be used in a passenger car. Also, while they make good horsepower, you have to rev the holy living snot out of them and spool the turbo in order to make that horsepower. That kind of engine would be useless for what we use FJ40's for.
The 1FZ-FE was offered in the 93-97 Land Cruiser, is a great engine, but you have limited transmission options for that. Since you've already got, I assume, an H55 transmission, you'd need to find a bell housing out of an FZJ-70 to make it work (this is somewhat rare, from what I understand, as most 1FZ's were offered with an H151 manual, which has a different bolt pattern). Also, the 1FZ-FE is very long, so you need to deal with that. Eg radiator placement, driveshaft length, etc. Also, you're on your own for wiring.
2F with 3F head. Also known as a 2FE. This is more easily doable if you have a later 2F motor with flat top pistons. If you have an earlier motor (a 1977 would have the 'early' 2F, if the stock motor is still in place), you have domed pistons, which would need to be swapped for flat top pistons for valve clearance. The 3FE head will give you electronic fuel injection which is a great thing to have offroad. There are a few threads on this, but it seems that the 2FE is a monster wiring project.
Another option, keeping it in the Toyota family, is to use a 2UZ out of a 1st gen Tundra, 98 -07 Cruiser, 02-09 4Runner.
For the work necessary to put in a 1FZ, 3FE, or 2UZ, I'd argue that there are better options. As much as I love the Toyota brand and would love to keep my 'Cruiser in the family, it's just not a great option, in my opinion.
3FE's were only available in 88 - 92 in the Land Cruiser. So parts are scarce and harder to come by. Worse, many 88 - 90 Cruisers were traded in on the Cash for Clunkers program and the engines destroyed.
There is also the Toyota Diesels, but these are harder to get parts for if you live in the US. You can't just go to your neighborhood Napa, Autozone, etc and get an air filter, or starter or alternator...
Honestly, if you want more power, in my opinion, the best option is going to be an LS based GM drivetrain.
you can get a LM7 ready to run with a cut down wiring for about $3000. Much less if you're willing to do the work of cutting the wiring harness down yourself. Also, this is a very well known swap, and you can get pre-made wiring harnesses from a number of different vendors like Howell, Summit Racing, GM, etc (try that with a 2UZ, or 3FE).
