Registration varies from state to state. Typically, if you purchase a kit, you will recieve a certificate of origin and the chassis should have a number stamped on it. So long as you can link the chassis and the parts used to create the car you'll have no problem getting the car licensed. Emissions laws vary from state to state so be aware. Check your state government DMV website and look for kit built or custom vehicle codes. Whatever you do keep good records of material and part purchases.