Choosing the right tires & sizes for my Duster

I have 4 15x6.5 Rallyes that I want to put on my Duster. Now that the wheels are painted, I'm starting to think tires. I want 215/70-R15's on the front and I'm thinking 245/60-R15's for the back. Does that sound like a fair size? I want a bigger than stock rear tire without going overboard. However, just curious if the 245/60's will fit fine on the back without rubbing or anything? Anybody running this size on their Dusters? Also, I'm confused regarding backspace. I was told to look for 4.25" backspace? I'm of course thinking BF Goodrich Radial T/As but I'm wondering what some of you guys are running?