electric bicycle...
 

ok so my dad is giving me an electric bike (one of the schwin motorcycle chopper looking things) it has the motor in the rear hub and a battery pack that looks like a motorcycle engine (yeah kinda funny) anyhow im not the fondest of the seating and the front end rake so i am going to use the rear wheel to make a three wheel electric bicycle (2 wheels in front and the powered wheel in back) but i have also been thinking about getting another powered wheel like the one from the schwin and making it a 4 wheeler with a small distance between the two rear wheels. has anyone done anything like this before and does anyone know what batteries i should use to power this? i would like to make it a side by side two seater and have a 45 mile or so range. any thoughts / ideas would be wonderful

john