My advice, get the sizes and specs for your existing wheel-tire set up, then navigate over to this website:
Tire Tech Information - The Wheel Fitment, Tyre Stretch, Rolling Radius and Speedometer Error Calculator. Play with specs, try different settings, compare results
www.wheel-size.com
Enter all your wheel-tire specs into the left column, add your vehicle measurements into the side bar on the far left, then add the specs for the wheels and tires you are considering. Scroll down and it will tell you where your clearances are reduced compared to your current measurements. Recheck your clearances based on the calculations, and you'll have a good understanding of where you'll end up.