If your goal is build a lot of hours fast, you need a school with a reasonably sized fleet located in the southwest or FL. Make sure they only employ as many CFI's as they can keep busy. Some schools "hire" all their grads, but in reality that just means you're on call with no pay and you get to fly a couple times a month. In that situation you have to pay a lot of dues and kiss a lot of butt until they decide you're one of the few who gets enough work to count as full time.