In an attempt to reduce my overall weight in my pack and rearrange space, I had been using a thermarest and want to go down to torso only closed cell foam. I just got the Exped UL pillow and its so sweet and compact. It is the pillow I have spent quite awhile searching for. Im looking at the length issue I seem to have with pads. I want to get the GG foam pad and can't figure out the length I should roll with. Should I look at something that is just for my torso area and let my knee down just rest on the floor or should I just go full length? Im in a tarptent so I feel confident about the integrity of the floor. Just trying to go fast and light. I could double this pad as winter insulation under a z-lite or my inflatable.

I would say go with a torso length foam pad. You only need the sleeping pad up to your shoulders, since you have that pillow, and you can use your pack under your feet to knees, especially if your pack has any sort of padding built in. And if you tend to tent on ground (rather than on wooden platforms like in the Whites), the ground tends to be soft enough that foam pads aren't that bad for sleeping on, anyway.

I'd get a cheap blue foam pad and try it at different lengths to find your sweet spot. If you cut it too short you're only out a few bucks.