"Best" is a matter of choice, they're both good options, just depends on who does it and what you want.

If your primary objective is heat control then the ceramic coated exhaust is best. It's also going to have better longevity (than either plain or aluminized steel), and maintain good appearance. The ceramic coating is low maintenance, and shouldn't lose it's finish quality (depends on which color you choose as too whether it will be shiny or not). The headers might get discolored if the fuel mixture/timing is off at startup, but the rest of the exhaust won't see that kind of temp. Advantages are that a well qualified "regular" shop can bend and weld them up without having to have any "special" expertise. With the stainless your odds aren't quite as good, though with the more frequent use of stainless exhausts there are more qualified shops than in years past. In either case the pipes are likely to get some handling marks on them during the fab process (depending on how much of a gorilla the tech is), so with the one the cleaning/coating process will fix that, the other will require repolishing (if that's the look you're going for). Depending on operating conditions, and the quality of the stainless, it's likely the stainless will last longer, if you intend to keep the car long enough for that to matter.