Hello John,
Well, I agree with all the above comments about cost, provided you are going to do the work yourself. If you need to pay for labour for someone to put the car together for you then I don't think you have enough budget.
£45K will buy you all the parts you need to build a 400bhp street/track car with a great paint job from a kit. If you want someone else to build it for you, add at least £20k for labour.
A way through this dilemma is to find the right car secondhand, on which money has been spent which the owner will not be able to recoup in a sale situation. This applies to all areas of the classic car market, not just GT 40s.
I suspect that Martin Weigold might be starting to think about selling his car and it sounds like it has the right spec. to meet your requirements. Martin bought it as a very low mileage car from it's builder, Keith Baker, just over a year ago and has spent a lot of money on it since in getting it ready to compete in our Club championship. It is a GTD with all the right bits, replica seats and wheel, monster brakes, rod gearchange, rose jointed rear suspension and a fresh 400bhp 302 which still needs running in. If you think this might be the right route for you, you can see the car (and Martin) at
www.gtd40club.co.uk
Happy hunting and I hope to see you at one of our events this year.
Andrew