By 360x140 I'm guessing you mean a 420mm radiator (360 is 3 x 120mm fans / 420 is 3 x 140mm fans). Overclockers do sell a couple but don't have a massive range, so it could be worth a look around some more specialist watercooling sites, although with the 420's there doesn't seem to be as much choice as there is with the 360's.

Does anyone know if OC sell 360x140 rads, I couldn't seem to find any (maybe I am looking in the wrong place). I have F51 Suppressor case and want to take advantage of the 140mm mounting in the top for a wider rad.