1972 Duster Rim and Rubber combo

Okay, I have a 72 Duster with a /6. I did a SSBC conversion on the front drums last year, and I'm getting wheel adapters to run the 5/4.5 bolt pattern all around. I will be using the following rim http://www.americanracing.com/wheel...piece polished alloy, forged center&section=V

I want the rim to be a 15" rim, but the width on the front and back is my question. I don't know what rim/rubber combination will not only look good, but also fit without the spring relocation. I want to run a wider rim on the back, and smaller on the front, but how wide or narrow can I go? Also, what size rubber would best go on both the front and back rims.

If you have any ideas or criticisms, I would gladly hear them.

-Bthieson