a lot of people will tell you the same thing.
Yes it can be done, it is not too easy and not too hard but there is a lot to change. Best bet is to find a whole car and switch all over. I think I would find one that needed bodywork and just swap all the good sheet metal over, much cheaper and easier plus you would still have a real GN or T Type that would be worth something.
I am just about finished with my swap and if I were to do it again I don't think I would. I already changed the rear and trans previously so all I had to do was the engine, wiring and fuel plumbing. I began over 3 weeks ago, hopefully will fire it up this weekend.
Save yourslef some time and some money and just pick up a real T or GN