My PFD goes under the end of the sleeping pad to get some lift and my pillow is this one   (You need to Login or Register from REI.  It compresses near flat and goes in with the bag and air mattress.  The shape keeps your head cradled, you can adjust the inflation amount, it has a soft feel fabric, and the bottom has rubber strips to keep it from moving around in the bag.  There are two things I'm willing to spend extra on for my comfort - sleep gear and rain gear.  Nothing beats a good night's sleep.

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