contemplating build

[El Poocho]

Hi ive been intersted in building an ebike for a few years. Now i have the time and bucks to. im just wondering should i build DIY ? or full piece from amazon? hmm... anyway hello all im from white rock canada, and glad i found this forum as I have many technical questions. my first is how many watts should i go? and what does wattage mean as oppsed to amps? etc, etc.