Venice motor bikes sells a disc brake conversion kit with caliper adapters and disc compatible wheels as well as the complete disc brake setup. He started out making the adapters just for springer style forks, then said he now makes adapters for any style forks. I havent looked at his site in quite some time, so idk what is pictured there. Your best bet may be to call him and ask what he can do for you. As far as registration and a vin, I'm not sure what the process is in your state, but here you have to have an enhanced vehicle inspection to prove the bike meets all requirements (this is for mopeds, no idea what it takes to register as a motorcycle), then have the inspection form notarized and send it in with a title request to the dmv. When you fill out the title request, you can put the bike's s/n as the vin. You can also have a plate stamped with the vin, then attach it somewhere on the bike that's easily readable. The process may be similar in your state, but I can't advise you on that. You should google it, and maybe call the dmv as well. I can tell you that almost everything on the bike will have to be DOT approved to meet motorcycle requirements. This means lights, directionals, wheels, brakes, etc. Just something to think about. Good luck bro.