Conversion Kit from http://www.cyclone-tw.com/ :
3kW Electric motor
36-72v 40A Controller
Crankarms
Chainwheel
Thumb throttle with Key
Building a battery
(52) 18650 Cells in 14s4p configuration, 52v 12Ah 60A
Samsung 30Q, 15A cells
Solderless system from https://vruzend.com/
Custom 3D-printed battery housing filled with oil.
Visit http://www.ebikeschool.com/ for more information about building your own ebike with really good tutorials for building your own Li-ion batteries.