I'm looking to buy my first sleeping pad for an upcoming multi-day hike. I have camped many times over the years, but never while hiking so I always slept on an air mattress.

I see as part of my difficulty in choosing a sleeping pad that I am a side sleeper not a back sleeper; it is almost impossible for me to sleep on my back and always has been. I need something thick enough that whether sleeping in a tent or in a shelter I wont have my greater trochauter pressing against the ground thus causing me pain and discomfort (and not being able to sleep).

I should also note I am 6'3" and 215 lbs, which probably factors in there too.

How thick of sleeping pad should I be looking?