Ok. Before we go any further, lets get a few things correct.
First off, if you're planning on doing this swap yourself, I have to ask are you a mechanic, and if not, have you ever done a transmission swap before ? If you don't know what you're doing, you can end up doing more harm than good. If that is the case, then it's better to let someone who knows what they're doing do it for you.
Second, if you're planning on putting a blower on the car, then what might help us help you in terms of advice is for you to tell us how much boost and power you're planning on making. If you're planning on making over 400rwhp, then you might want to look into either buying a 4r70w automatic and upgrading its internal parts, or buy a high performance 4r70w transmission from some place like Performance Automatic or Lentech Transmissions.
If you decide to upgrade a stock 4r70w, I recommend you read up on the tech articles over at
www.tccoa.com Their tech articles on the 4r70w transmission are the best at supplying info. on the 4r70w automatic transmission.
Either way, you need to get a transmission cooler for that automatic, or it will not last. Also, be sure to run a good transmisison fluid through there, or it won't last either. Whatever fluid you get, make sure its at least Mercon V or superior.
Let us know if you have any other questions.