Thanks everyone for your comments and suggestions, especially 46gmcpu!! That link describing a side by side comparison of the 700R4 vs. the 200R4 sealed the deal for me. The 700R4 is far superior, and for my application it's all I need and more. Had originally thought I'd put in a Turbo 350 like everyone else, but the overdrive and increased MPG prompted me to look into buying a 700R4. It may be a more difficult installation, but I think it'll be worth it in the long run.
Thanks again!