One item to consider is the 700R4 (aka 4L60) has a 3.06 1st gear ratio as apposed to the TH350/TH200R4 which is in the 2.50's range. So if you have a 3.23 to 3.50 rear gear and a 700R4 it make the vehicle feel like it has 4.11 - 4.30 with a TH350 installed.
Locally we can get good used 700R4's for under $200. If you do need to rebuild a tranny the 350 is Much cheaper to do than a 200/700. A good 350 rebuild is around $250 in parts.
Either transmission will do a good job. Just depends what you want to do.
