"What KIND of Trans should I be looking at and why?"

Jeri, if you want some gas mileage on the road, you will want to consider a 6-speed transmission with 2 overdrives (OD) to get the engine rpm's down. The faster the engine spins, the more gas it uses and if you can slow it way down on the highway where you don't need a lot of power to move the car at a steady speed, you'll be able to pass some gas stations.