Getting an automatic rebuilt can get costly. They typically quote you one price but it always end up costing more in the end. If the price is anywhere near the cost of a new one I'd probably considering going that route, particularly if the warranty is better. If the warranty is much longer on the new unit that would likely be the better route, particularly if you plan to drive it hard.
The last auto I had rebuilt was from an Explorer. I was quoted 1300 and it ended up costing over 1700. For 400 more I could have got a new one with a much longer warranty. I learned a lesson on that one.