FastOlson, Thanks for your input. I found a article about using Phifertex from about 20 years ago. It said in the tropics you need all the air circulation you can get if you want to sleep. Glad to hear all the good thing about it. Will definitely try it and for cold climate throwing a blanket over it to add extra warmth would be simple enough. I like your snap shackles not sure where you found them? may go with plastic quick release buckles.
Only question now is overhead securing or forward and aft to bulkheads , or both. definitely need to be able to drop one end quick to get out quick.
Also a pocket on the out side for clothes or personal stuff, Thanks for everybody's input.