We are about to go on a week long tour of southern Utah. Many nights will be spent camping at national parks so no hammocking allowed. Which leaves me sleeping on my thermarest pro light 4 which is brutal on the back!!! I was thinking of getting a big thick open cell foam pad but I wouldn't know where to get it. REI makes the deam time XL but $200 dollars seems a bit steep for a pad that is only 77x25x3. I know I've seen nice big foam pads but I'm not sure where. Ideally I'd like to get something that is 50" wide, then my wife can leave her thermarest at home as well.