Just a note on the reason I use a stretcher for my platform:
Stretchers are made to be supported on four legs and therefore require only 4 points of support from the webbing. Most camp cots have either six legs or 3 wide supports, which would require 6 points of suspension from the webbing, complicating the rigging and somewhat interfering with easy access.
I like the full-length straight-line support of a stretcher, but it is a bit narrow (the better to squeeze more of them in a military ambulance, I suppose).
You can get them at your local military surplus store for 20-30 dollars. Add 10-15 dollars of webbing and a little creativity and you're sleeping like a baby.
regards,
-Peter "Knothead" Hedin
