Since the car is already street legal in France I would think a change of ownership and getting French plates again should not be a problem?
Good luck with the car - to me the specs seem very good for a GTD !
As far as fuel pumps for carbs go any race parts store should be able to help you (I usually turn to Jansen Competition in Austria or Raceparts, Merlin in the UK). For fuel injection I recommend Kinsler in the US.
Any workshop specialized in this type of car are company like Ecurie Europe that support race car or Lady Art Car, a professionnal restauration workshop, but they will cost you a bundle. Do not go to Alternative car that displays GT40 on its web site, you would be very desapointed.
I have a friend that has a workshop for rally, or track cars with all the equipments in house to take care of such engines, very professionnal, the only problem is the execution time...
He is located in Jura, ask for Samuel Pezot, 03 84 25 29 84