A mate of mine 6' 10" had an extra long bed sent to Bosnia and a corrimec to himself, he also had a chit from the MO (which was fabloned), allowing him extra scran. If he didnt eat like a horse, he would waste away. Lucky bleeder.
I am absolutely certain that at least once in my career whilst out the back of a Q stores somewhere I saw a pile of bed extensions. It was a frame similar to the normal bed fram with legs and two metal hooks to lock it onto the end of a normal bed, so the post about a 6 legged bed is almost certainly spot on!