I believe you've been talking to my brother about our boat, Bad Fish. We use a similar set up.
That motor/lower unit looks a little old but if the brushes are good in the motor all you should need is a speed controller, a bank of batteries, and a LOT of spray paint to get going.
I'd actually be interested in knowing what lower unit that is and what gear ratio it has. It looks quite old but it has a lot less surface area in the water than what we run.
For the record, yes, we are the guys that are excited to see 5.5MPH on the GPS.