Well, pretty much decide I'm going to go with the 6hp Tohatsu Sail Pro.
http://www.tohatsu.com/outboards/6_4st.htmlIt's the only 6hp 25 inch shaft out there I believe. In Merc you can get it in a 5hp. Nothing in Yamaha.
If price and weight were not factors I'd probably go with the Yamaha 9.9 HT. I just don't like the extra 40ish lbs right on the transom, and that much more weight for me to lift off/on. Boat sits in our driveway and I'm not going to leave it on with some dinky outboard lock so some crack head can swipe it. Don't want it permanently bolted to the transom as from time to time I'd like to go fishing without the kicker off. For example just fishing the Vedder canal for salmon I'd probably chance it and leave the kicker at home. One less thing in the way on the stern for netting fish. However most of the time I'll probably have it on the boat.
I like that the Sail Pro model has a high thrust prop. I know this will still not likely push my boat against the current in the Fraser, but if my main motor was disabled I'd be mostly concerned with just getting to shore, which I have been told by a few shops the 6hp HT Tohatsu should be able to accomplish.
Ive also decided to go with the 25" shaft. Seems the consensus is the 20" would be fine as just a river back up. However used for trolling the 20"shaft would likely cavitate in waves as the cavitation plate will be sitting right at the water line.
Unfortunately I do not know anyone who can loan me a 6hp motor like this to test out. I'll just have to trust the advice of the guys who sells these motors and if I really am not happy with it sell and and go 8 or 9.9 next time around. From what I have read and been told I feel I will be happy with the 6hp Tohatsu high thrust.