Thanks for the information and advice guys. It gave me things to think about. ebijacks comment on having a way back in if something goes wrong is absolutely worth considering. And since wakina can move his 23 footer along well with a 9.9, I'm sure I could save some with an 8 hp and it would still do the job on my boat, which is lighter. So that is likely the way I'll go.
My wife's birthday is next month. I wonder what I should get her? Hmmmm..