Glen, though several have responded to your wheel choice, the car is beautiful! Of the last of the original series Mustangs, that Mach 1 is a stunning design. Many miss that the styling cues were to invoke the later Ford GT 40 "J" model with its aerodynamics.
I purchased a power rack & pinion setup for my 67 Mustang coupe from a fellow several years ago that had the same year but was a Shelby convertible in dark green.
I also modified mine to have 2010 Mustang GT 4 wheel power disc brakes. That required 17" Bullit wheels to clear the brakes. Can't tell you what an improvement in steering and handling not to mention the better (actually-"its gonna stop) braking.
The owner of the Shelby had installed the R&P for more comfortable driving. Decided to convert it back when he wished to sell it. My point is that "bolt ons" can be switched out for those that need originality. But the wheels can always be switched back. Its your car & your choice