Oh...…. oh...……..……………………...maybe 70 is the new 50...…………………………..When I turned about 64ish I just didn't have those 10 hour days in me anymore. So I guess what I am saying is, if you are young then you may not have as many days that you can build your car due to work, family, etc. but you can catch up on the weekends with a full and long day of building and a few mid week short sprints after work. But as you get into your 60's it might be better to buy the car at least some what complete and get right to driving it before your body just doesn't want to work out on the cold concrete floor for years on end.
Then there is the other thing...…………….. The car you "thought" you wanted to drive at 35, the 700hp rocket one, isn't what you really want to drive when you are 65. The hands just don't work that fast 30 years later and the eyes can see a damn thing!
Either way the entire hobby is a wonderful journey.
As far as what car? I really believe that all the major manufactures offering cars today are pretty far along the development curve and are selling a car that really is well conceived. In other words at this point in time you really can't buy a bad design from the current crop of gt40 "kits".