I'm not worried about the bolt pattern, that isn't the reason for the question.
An off the shelf bolt in wheel bearing hub assembly would mean easier maintenance and (generally) the hub carries the tone ring for the speed sensor. And if setup right, all available brake options for a late model Mustang would be possible. Like carbon brakes off a GT350R or whatever.
Certainly a custom hub with a tone ring would be an option, just seems like the wheel bearing cartridge setup would be easier.