personally id stick with a 2.4l engine. They are easier to work with and a lot more reliable then the 3.0l. I have owned a 1990 4runner with the 3.0l and a 1991 toyota pickup with a 2.4l. The 3.0l had the most problem and triying to do any work on it on your own was a real pain in the ass. Also upgrades for the 3.0l is very expensive and you can get a 2.4l and add power mods to it and exceed the power to Cubic inch ratio cheaper then what you could with a 3.0l. If your going to do a swap and stick with toyota engines i'd go with either the 3.4l or a supra engine. Personaly id go with a chevy motor.
Just my .02