I don't have much for comparisons...
I like the idea of a heavy duty manual... but that is a pretty big swap to do, and it all adds up dollar wise.
The th350 to 700r4 should be a bit easier, you will need this adapter/spacer.
http://www.advanceadapters.com/produ...with-gm-700r4/
Do you have anything that supports your 205 transfer case other that the cross memeber? If not, you may want to get something like a torque rod or an after market brace for the back.of the 205. See the pic of the torque rod.
You should be able to use your current th350/205 adapter... double check me on that, Google says yes... and everything you read on the internet is true. Lol
You will also have to move the transfer case back a little bit, more than a couple inches, less than 5 I think. This creates driveline modifications... or you can try and move your motor mounts forward and split the difference.
I have always heard that 700r4's are a crap tranny, not being known for liking oversize tires or towing. On the flip side, I have known a few people that have had them built with abuse in mind and they have been solid, no issues. That is what sold me on them. Personally I didnt want to spend the money on the 700r4 build when the th350 fit my needs better. (Note, run a big tranny cooler)
For what you are looking for I would go 700r4., Taking a quick peak on line, it looks like it will be your cheapest option.. depending of course on how crazy you go with your transmission rebuild. I saw that you could have a stout 700r4 for under 1,500... looks like 1,100 for a stock rebuild on line, shipped to your door with a 24 month warranty. .
I hope this was helpful, and Good luck!!!
Let us know what you decide!