Will this setup work? If anyone knows let me know, thanks

 

look at the specs of the tire... if it fits a 18x7.5 inch rim according to the manufacturer of the tire then I don't see why not... just realize that you speedometer will run faster than you are actually going because those tires have to turn more times per mile. (see the sticky about the tire calculator to see how much)

 

yes, that is the optimum size for that rim width.