i had an post in the for sale section looking for one (i know i should pay attention when posting)
there were a few people that replied in there about it.
For the price i would pick up a zc engine and put in that, it's going to be around 1000 for the engine depending on where you get it and it will give you a boost in power.
i've been told to stay away from the 96-00 engines due to oil problems and to swap them into an obd0 car is a pain. but that's what i was told, so it may not be true.
btw, if you decide to sell the engine that's in your rex i'll buy it for the right price
i'd love to get that kind of gas milage :).