As Don says, get ahold of DMV, and talk to the inspectors. Even though your not required to go through emission testing where you are right now, ask what the requirements will be, as the car will have to go through at least a level 2 inspection when its titled and that may be a part of it.

As a specially constructed vehicle it will be be titled and be required to meet the safety/emissions requirements for the year you get it titled.

THEN, after you have the information from the DMV, go to the Cochise College book store and buy a copy of "Title 28 Transportation Laws of Arizona" This is the bible in Arizona for regestering vehicles and sets forth the minimum safety requirements. When/if you ever get the car buillt buy a current copy to ensure the laws havent changed between the time you started and when it is completed.