I'd build the original long before I'd build a clone. We have three A-body convertibles in the family. The GTS is mostly correct (non-original 340, 273 valve covers, sport caps and steering wheel on a car that was not built with them) with very good docs (two broadcast sheets, fender tag, stamped #'s, original owner's manual with first owner's name, and first California registration from the second owner in 1970) .
The other two are hot rods (440 powered.....well, mine will be if I ever get it done). They are a 67 Dart GT (my son's, 440/4sp) and a 67 Barracuda (mine, 440/727).