One more thing. Unless you spend the big bucks, you will get a pretty poorly made bike, with a first-generation drive. That will probably be okay for the distances you are going. It will also buy you some time to build up from a kit. All you need is a good quality bike, a kit and a few hours time.

Assuming you are going with the pre-built, keep in mind that manufacturers are very optimistic about both range and speed, even with full pedal assist. Don't let your SLA batteries go fully flat and un-recharged. You may only get a couple of hundred charges out of them at best before they become landfill.

Good luck!