Wow, you must have some awesome hills there. Seattle is bad enough, but your town sounds tougher. Is the push-button unable to power you over the steepest parts?
If the Urban doesn't work out, take a look at a couple of iZip bikes. The Ultra has a 500W motor and is pretty fast. It is spartan compared to the Urban, and about the same weight (without fenders/rack/lights/etc.).