It sounds like you are looking for a serious system. It may be too late as you may have already bought a bike but here are my two cents. Bionx: great company but there is more bang for your buck out there. I recently was int he market for a seriously powered electric bike with massive range as I too am a commuter The only way I discovered to get a 50 mile range was to go with a 20 AH LiFePO4 48V battery. If you're looking to charge while at work you could also go with a 10 AH or maybe a 15 AH battery just to be safe. As far as chargers go a 4A charger should be able to recharge a 15 AH battery in 3:45 and a 10 AH in 2:30 so that should take care of you. If you're looking for some top speeds no one out there is better than Electrified Bicycles (well Optibike claims to be, but they run about ten grand). These guys can get your<mode edit--shill link removed> running at speeds up to 40 MPH. I had live in a similar area as you with some hills and such so I went with more of a torque-y motor and so top out at speeds of 33 mph.

In all before you buy a bike I'd check these guys out.