Re: saw chopper bikes on youtube and had to get one :)
I get the wanting one (OCC) thing. So I built one for my second bike. Tougher to build? As I see it this bike only needed some customized items. Mainly the motor mount. Mine is from Bike Berry and so is my exhaust. You may want a smaller than a 44T sprocket. I have the 44T which provides great low end torque on a 20" wheel, but limits the top speed. Lastly, as others have said this bike is kinda small for an adult so I replaced the handlebars and reduced my seat post size to 1" and added a lay back seat post with a 13" wide coil cushioned seat. Now the ride experience feels like I am no longer cramped. There are few other bikes that when finished look like a small motor cycle with peddles!