Well you can build the frame you want, you need a quality tubing notcher, there are some effective ones that use hole saws and appropriate clamps that do not cost a fortune. Some 4130 or 4140 tubing as used in WW2 fighter plane frames, enough scrap for jigs to secure the tubes for welding and if you do not trust your own welding, tack it up then find someone like me with a tig machine in their garage along with the appropriate skills. I would sew a frame up for you for free, just to be part of a cool project. You have a bike to ride, so slow down your timelime and it will eventually come together. Or build it as an alternate rider. Look on the positive side, you have many parts you can utilise from the frame you have now, such as a frame neck and the forks to fit, the motor mounts ready to be transplanted to the frame you build, a good jumpstart on what you want to build. I will even loan you precision levels and mercury plumb bobs if you ask. BTW, I have been building a 750 twin Kawa Bobber for three years (the design keeps evolving), no big rush, because it's for me.
