New bike: Leaning in this direction

I am currently leaning in the direction of this bad boy: The Pedego Trail Tracker...

Motor Brushless Geared Hub Motor on Rear wheel
Power Rating 600 Watt
Gears & Speeds Single Speed
Batteries Lithium in a Removable Pack
Charger Smart Charger Included
Amps 10 Ah Standard – 480 Watt Hours
Volts 48 Volt
Tires Vee Rubber 26″ x 4.00″
Speed 20 MPH using motor power only
Distance 15 – 30 miles per charge in throttle mode 
                  (depending on rider weight & terrain)
Throttle Type Twist Throttle Variable Speed Control 
Frame Type 6061 Light Weight Aluminum
Handlebars Black 5 inch rise
Braking System Avid BB-7 Front and Rear Disc Brakes
Drive System Rear Hub Motor (Motor is in rear wheel)
Measurements Frame Size 18″
Axle to Axle 50″
Handlebars 27″
Seat Padded Adjustable Seat 
Bicycle Warranty 1 Year
Battery Warranty 3 Year Limited Warranty

I would still need a few add-ons:
Cushier seat.
Cruiser handlebars for more upright seating position.
Security device to lock it up while traveling.
Security device to lock it up in garage.
Electronics (mapping, speed, distance, etc) will be via iPhone 5s.
Lights.
Helmet.
And probably a lot more stuff I'm not thinking about right now...