[Stumble]

Check on craigslist. I picked mine up for about $75.

 

[Stumble]

I can't speak to everything on craigslist. The ones I have bought were in decent shape, used but not abused.

 

[Stumble]

I used a 45lbs motor on a 30' 3600lbs boat. In dead calm days we could hit a whopping 2.5kn. Into a headwind it depended, but generally we would just sail. You are heavier and shorter and thus will require more power... You probably need to go to 24v honestly, at least if you need to go any distance. If not try it with one and see how it goes.