Are the wheels steel or aluminum?
Most wheels designed for 60 degree conical seat lug nuts are drilled .60" to .63" anyway, so overdrilling them for 5/8" studs really doesn't usually need to remove much material. That said, what size are the through holes now?
The shank type lug nuts are a waste of time unless they're virtually the same size as the through hole, as they'll just center on the conical seats anyway. That said, if you make hub-centric spacers for the wheels, then you can retain them however you like so long as they're not at risk of pulling through the wheel.