you can't go wrong with Army Poncho Liner.

However, i have a Therm-A-rest Tech Blanket and love it. I use it for all my traveling and car camping now. I am 5'10, fit but wide in the shoulder, I have the regular and it feels just an inch too small snapped together but not enough to deter my use. My next will be the Large. If you buy the fitted sheet as part of the sleep system (it goes over your air mattress) there are snaps on the fitted sheet that mate to the Tech Blanket which makes it just like sleeping in a twin bed.