I would definitely recommend the Klymit Static V pad, non-insulated one is around 16oz r-value 1.2, a pound and a half for the insulated one r-value ~ 5.0
The way its designed, when you lay on it and your butt/hips push the air, the air moves to the side square chambers, which balloon up slightly, preventing you from rolling off and preventing the V shaped sections from ballooning, creating pressure pouints. All you gotta do is inflate it, lay on it, and slowly let out some air until you're comfortable with the firmness.
Its one of my favorite pads, and I've used it comfortably down to the upper 30s with a sheet of reflectix underneath.
The Big Agnes Insulated Air Core is nice too. I use that when its colder. Short (60") Mummy version is 18 oz, with an r-value of 4.1 The vertical (head to toe), baffled tubes are very comfortable to lay on, again, filling it all the way and letting out some air once on it.