3RZ's have had issues with the ex. manifold cracking. So be wary of that. Also, 95.5-00 Tacoma's have issues with rusting frames, so check that out, too. Toyota is doing a 15 year extended warranty on the frames, so nothing too much to worry about.
But, FYI, a friend has a 2.7L Tacoma 2WD and it doesn't seem to get any better mileage than a 4WD (of course, the 4WD being kept in 2WD). If it were me, I'd opt for the 4WD just for the resale value and more fun!
