When I was into airplanes, I used to see guys buy a decent airplane designed for a particular use, and then spend tons of money to modify it to get it to nearly equal another production airplane that they could have just bought, sometimes for much less than they tied up in the project plane.
My advice FWIW, decide what you are trying to end up with and see if someone already makes that bike. BTW, I ride a TLR200, different sprockets, foot pegs, bars and non battery lights.