'01 Tacoma 4WD or '03 2WD

I'm trying to decide betw an '01 Tacoma 4wd w/30k miles or an '03 2wd w/locking differential w/6k miles. Are there any major engine changes betw 01-03? I'm also wondering about the dependability of the 4wd vs 2wd. I don't know the history of either but have a partial repair history on the '01 which lists: Ck brake vibration (it still does this w/what looks like new Michelins; rotors perhaps?) Ck valve or lifter noise/smoking (can't hear anything now) Were the '01's known to have any bad big ticket problems. I'm kind of afraid of the brake vibration and tire shudder because of what was posted in an earlier thread and having dealt with the same thing in an Explorer. The '03 didn't seem to have any kind of brake or tire shudder. I'm inclined to go with the '03 because I'll be putting @30k/year on the car, but the 4wd would be useful from time to time on the farm. thanks for any advice