A rear hub system makes sense for your application. You don't need a "great" bike since the motor will really help, but a steel frame will provide a better platform IMO. I've purchased a couple of 90's or so steel bikes on Craigslist that made excellent conversions. Also, a 26" system will give better acceleration, all other things being equal. OTOH, Lectric Cycles < $1000 bike seems to have good reviews, including one done after three years of use. You can get plenty of help here should you need it, but beware of the drone(s) that will try to steer you to an expensive OEM bike because that's what their store sells.
