Exped makes some long wide insulated mats that are worth a look. I am about the same size and have the long/wide downmat. Slight weight penalty over the neoair style pad but definitely backpackable and warm, quiet and comfortable.
I have a downmat 7 with the integrated pump--warm and additional width does make it more comfortable for me. They make a lighter one with an inflation bag but it wasn't available when I got mine. I've had it since 2011- 12 and it has held up well. I've tried other lighter pads that had a better warmth to weight ratio (but not as warm absolutely) but did not find them to be as good all around, factoring in the comfort (and quiet).
I used long wide xtherm and static v. Both were fine.
Really liking this guy from sea to summit. 4 inches thick means no bottoming out when on my side. R value is a little on the low side but I have had mine down into the teens and been warm. I run the regular-wide rectangular version. I am a side sleeper so it is plenty long for me.
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So many variables to consider... Are you a side sleeper or back sleeper? How many consecutive days are your trips? How cold is the temperatures you camp in? How far do you pack your gear in?
I'm 6'4 250lbs and I'm a side sleeper. I own an Exped, 2 Thermarests, and a Sea to Summit. They all have pro's and cons.
I prefer the Thermarests (Uberlite and Trekker) for light weight early season quick trips.
I prefer the Sea to Summit Comfort Plus for overall comfort and warmth. I really can't say enough about the comfort of the individual air sprung cells. If you roll around like I do, they don't transfer air from your hips to your head like a typical sleep pad does. It has 2 separate air chambers, an upper and a lower so if 1 loses air the other stays inflated to keep you warm. It also has the best inflation system out of all of the others I've owned. The only con is it weighs 2 lbs 4 oz for a Large size.
The Exped Downmat 9 is great for extreme cold temperatures.
I like the Therm-a-Rest BaseCamp Sleeping Pad in XL
It is big and well insulated. I have used it at -10
I am as big as you and I am a side sleeper and don't hit bottom
It does weight 4 lbs, but I don't care after a long day in the field, it is worth it.