Cobra manufacturer decision

I think I now know the manufacturer, but this is a personal choice. From all accounts AK and Gardner Douglas (GD) Cobra replicas are both very good.

GD seems to suit me best. Why?

a) good GRP body, that is semi-monocoque. I will go for a Mk4, which is like the 427
b) roll hoops that are attached to the chassis, so should work in the event of a roll (but hope to never test this)
c) some protection in the body for side impact (again hope never to test this). There are steel bars in the doors and foam filling in the sides to help absorb a side impact
d) I like the engineering of the backbone chassis of the GD
e) relatively light for a Cobra replica
f) is said to handle very well, especially on the track
g) road ride quality is superb for a sportscar

Now I need to work out what decisions are required to move this dream forward. Some of the key decisions and actions I will have to take/make are shown below.

a) secure a build slot (looks like September 2015) for a small deposit!
b) decide on chassis type (GDJAG - uses XJ6 donor parts or GDEURO - latter is a fully built rolling chassis and costs about £3k more, but allows registration on a new plate, subject to the engine and gearbox - see below)
c) decide on engine and gearbox type and whether to go new or used (about £3.5k difference)
d) decide on the ratios required in the diff if a GDJAG  (it will be a limited slip)
e) colour required - not yet decided on gel coat or paint

Decisions b,c and e need to be made a no later than a couple of weeks before manufacture because of the engine and gearbox mountings, plus the gel coat materials.