Where can I get a 48V Free Wheel Rear Bike Kit? I was looking to purchase the Amped Bike Front/Rear geared 36V 350W-450W kit, it's a little pricey at $531, but it free wheels and is only 9lbs. Also, it has 15% more range and 8% more torque than their other kit. However, I was told that a 48V kit would give me greater acceleration. My question is what battery should I get? When I was last doing research on batteries PING was the best bang for the buck, is that still true?I would really like to have a bike that takes off fast as I have a lot of stop lights, stop signs on my route.