tire size reccomendation please
 

I have a 2006 Mustang GT and I am getting 20" Foose Nitrous wheels, 8.5 in the front 10 in the back. I have no idea what tire size I need for them....a guy I know has the same wheels and car and he recommends 255/35r20 in the front and 285/30r20 in the back. If anyone could reccomend some tires it would be appreciated as well....right now I have been told to get Hankook.