What is the biggest tire that you mount on a 2007 wrangler x stock it currently has 15 whls what would be better a bigger tire or wheels will the rubicon standard whl tire combo fit?

The 2007 Rubicon wheels/tires will fit. You will have to have the computer reprogrammed to compensate for the larger tire size. Definitely worth the investment because it really gives the Jeep a beefier appearance.