Looks like 2.4 is the largest front but they do a 2.6 rear, I've run a narrower front/wider rear on a weird mullet setup before but I know I'm a weirdo, isn't it usually the other way around?
My frame definitely has more room than my fork though so...
The current continental line up is excellent and the naming standards for casing and compounds is easy to decipher. I think they only do 2.4 though