71 Dart Swinger wheel/tire combo suggestions

Hey guys, posted this on the A body FB page, figured I'd ask here as well. So right now I have 14" rallyes all around and I am in need of new rear tires. Instead of replacing them I would rather upgrade to 15" on the whole car. So I found some black steel wheels from Wheel Vintiques on SummitRacing.com that are 15x7 sbp with a 4" backspace. My question is: with these wheels what would be the ideal tire size front/rear? I have all stock suspension, nothing modified, as well as an 8 3/4 rear end. I would prefer the rears to be wider than the front. Probably going to go with a Cooper Cobra brand tire and buy them from Summit as well.