The 3.6:1 gear ratio with 10.35 MPH top speed would be a good choice if you want the motor to help power the bike up steep hills, and the 2.4:1 gear ratio with 15.52 MPH top speed if the hills are gentle.
I can definitely put together a list of parts for the project. For a 400-500 pound vehicle to climb hills with the 650 Watt gear motor a 5:1 gear ratio would be best so the motor puts down a lot of torque to the wheels. There are a lot of different battery sizes to choose from and the size of the battery charger depends on the size of the batteries. The larger the batteries the more ride time the bike will have. So I can help you choose the right size battery pack, how much ride time do you want the bike to have when it is being powered by the motor?