Hey there. I would say the 1UZ. They are cheaper and you will have more fun with it. It's going to cost you more to put the 2JZ and it won't get better fuel mileage. There are more people who can help you out with a 1UZ swap as well. I know a few people over at
Lextreme.com have put 1UZ's into Troopers.
The 2JZ is also longer. It would be harder to put into your engine compartment.