If the two trans are similar in price go with the 700r4. With the 700r4 you'll have to get a lock up kit for the forth gear. They cost about 150 though summit. I am going the 700r4 route with my motor swap. Thats my 2cents.
If you want i have a turbo 400 id cut you a deal on. Was going to use it but then got a good deal on a built up 700r4.