I went with a 33x13,18 and a 2" leveling kit just for reference. The link below is a Metric to Standard tire conversion calculator,just plug in the size you want and it will do the math for you....
http://www.redrock4x4.com/tech/tire_...method=metric/
Also I got the wheels and tires here.....
www.ntwonline.com
........ and I was very happy with the service,these guys are a class act and thier prices are very competitive, I'll pay $50 more for the pleasure of dealing with somone who knows what they are doing.(versus ebay or other shady online places)