The issue individual cook stove for the average squaddie was the hexi cooker. The British Army small individual cook stoves are difficult to come by and there are few if any replacement parts. Army Stove Nos. 6 & 7, Optimus No 111C are all correct stoves for the era however, Squaddies often purchased commercial stoves such as the Coleman Peak multi-fuel rather than struggle with explody petrol cookers or heximine. Several of the lads currently carry the MSR Pocket Rocket stove as a stand-in for the slightly larger Coleman stove.
The UK 24 hr Ration Packs do not come with flameless ration heaters like U.S. Army MREs therefore if you want a hot meal when on British rations you'll need hexi or a stove of some kind. If you are using US MREs for your meals then you can conform to the US requirements for stoves and cook-wear. Due to the presence of flameless ration heaters in the US MRE the need for a boiling vessel to heat your food is not a required item.