Over in the mreinfo.com forums, Jayuk mentioned that he just found some new flameless ration heaters(FRHs) that looked like the US version but where big enough to handle Canadian and UK entrees. Check out his post in the forums.
Here are a few sample pics. The first is a British entree, a Canadian FRH, and a US FRH together. The next two pics are of the FRH's text in English (the other side is in French):