I am looking for a programmer that will raise my shift points, increase shift firmness, allow me to adjust for steeper gears, run an off-road x or h-pipe, and provide and increase in horsepower via advanced timing. What is really the difference between the diablosport predator, hypertech, superchips, and sct tuners? What would make me want to choose one over the other, and where are the best places to purchase each of these from (i.e. who has the best prices?)