Convoluted mess, Wheel help please.

[-Freak-]

Hey guys, could use your help.
I'm doing a Mustang II conversion on my 70 Dart and ran into a possible issue with the hub size on newer mustang wheels. I really wanted to be able to use the FR500's because they look really good and are priced right.
But it seems the Mustang II hub might be to large for the wheel. Is this going to be a common theme with the Mustang II hub/wheel fitment?

Current setup.

Front and back are 5 x 4.5
Front: Mustang II spindles/hubs/brakes on a custom K member.
Rear: Mopar 8 3/4

Is this going to be a pain in the ass to find wheels for?

Shawn.