Great Project! I am considering doing the same with a small (22-23') sailboat and a couple of trolling motors. A couple of 50lb thrust trollers should be more than sufficient to move a little 2300lb boat. Lead acid batteries are dirt cheap at around $50/kwh! It's too bad I cant add them to the keel as ballast
I have a small electric generator, just in case I get in trouble and run out of juice.
Ill be watching you're project closely!