Mopar 15 inch wheel question?

My plan was to run 15x7s in the rear and 15x6 or narrower in the front with factory steel wheels to stay within budget and keep the junkyard build going. The thought would be to have the widest rear tire without tubbing the wheel wells and a skinny tire in the front to save weight. If I could find a 5 inch wide front rim, that would be ideal.