I mostly sleep with my left leg underneath straight at the waist and knee, and my right leg bent with both at the waist and knee. My left hip and shoulder have the biggest part of the pressure. However, my stomach (belly button) points more down than sideways. For the purposes of the mattress recommendations for the different sleeper types would I be considered more a side sleeper or more a stomach sleeper?
Hi Philmorse,
Welcome to the Mattress Forum! 
You would be what I often refer to as a “combination sleeper”, which is quite common. There’s a little more about this in this article. You’d want to choose something that has enough comfort on top for your shoulders, but not so soft or so thick that it allows your lumbar/lower thoracic region to sink in too deeply. I would generally recommend finding something that allows for enough support for your low back, and then “just enough” comfort for your shoulders, deferring toward alignment first.
Phoenix