Pete, I noticed this advert also, as it appears to be generated on a GT40 base. I've seen angled door hinges (top at the roof, and upper point of the lower door, if you know what I mean) on a replica, so that the doors opened forwards and upwards. This was not good. Gull wing doors would be better for access. At least you can open a gullwing when someone has parked close alongside you, and also have gas springs to hold them open. However, you may lose the use of the door pockets, and a big conduit of wiring has to go up the A pillar and across the roof to the door pivot and down for the mirrors, speakers, and central locking.
Dalton