Hey Zip thats one cool looking vessel you have there. I myself have been dreaming of powering a small boat with a trolling motor, but the significant other wasn't going to let me drop several hundred on even a cheap trolling motor and deep cycle battery, so I've just been dreaming for years. But recently I have been given a pretty good and powerful trolling motor and a battery so now its time to take action
I have a 17 foot two person kayak. I think with one person, a battery, and trolling motor that thing will scoot right along.
But the reason I am posting is to make this suggestion. If you have a heavy ole lead acid battery in that boat (and the other bits of metal and trolling motor) you really need to be sure if you get swamped you'll float well. I wouldnt count on that front compartment you have. With Murphy's law the second you get swamped is the time you'll find you didnt put that hatch on right like you thought you did.
A cheap and dirty way to ensure flotation would be to get a bunch of plastic jugs and tie em to various places on the boat (make sure you have enough). Another would be to go to Walmart and get the el cheapo camping/sleeping pads. They are blue, about 3/8 inch thick, 20 inches wide, 72 inches long, and are made of polyolefin and cost about six bucks. I've used em to make seat cushions and line the bottom of my canoe. I don't think the stuff will hold up to years of outdoor sun exposure, but it has held up to years of every weekend exposure.
If I recall correctly each pad will float about 20 lbs. Four pads should do you fine. You could glue them or secure them to the inside sides of your boat. The nasty non-water based contact cement seems to work fine with this stuff.
I'd just hate to see your boat end up in Davey Jones locker.