I've got one of Montane's Anti-Freeze down jackets that comes with a micro-fleece topped stuff sack so it acts as a pillow as well as a nice jacket. Result!
I reckon in this instance ttg is thinking of Mountaineering Designs in Grange-over-Sands.
I used them once, it could have been 10 years ago now, to refill a Rab double-layer down vest. They did a really good job - it came back as good as new, in fact better, it had a real Michelin Man look after they'd done their stuff
Bingo! Their the people I was thinking of.
As far as pillows go there are some mats that have pillows built in. Can't exactly remember them but could be those Exped ones or not.
I find anything soft as squidgy stuck inside the hood of your sleeping bag compresses up a bit to produce a higher lofted pillow that is contained within the hood by the hood's drawstrings. This is comfortable for me. Personally if you are tired then you wil sleep. What effects me more is noise. A choice between the worlds most comfortable pillow and a good set of earplugs then I choose deafness over a slightly raised head any day or night.
The guy who brought up the selk suit, in my opinion (IMO) I think a bag is better for sleeping in. I once spent a very, very cold night in down clothing and plenty of insulation to the legs. I was wrapped up like a michelin man yet I was cold. I do think a selk suit and a sleeping bag with equivalent loft of insulation have different warmth with the bag winning on that with less volume too.
I like the ideas of those topbags or even those quilts. But in reality is it as nice sleeping directly on a camp mat as it is on the flattened down plus camp mat that a full sleeping bag offers?
The one most important criteria I have for a night in the hills is that it must give me the sleep I need to recover. I never got that for years. The first improvement was a thermarest, the next was a thermarest pillow, then it was ear plugs (originally bought because the guy in the next tent on a group camp had a reputation for bad snoring) and recently it was an XL bag. The last one meant I could stretch out and didn't need to curl up just to fit in the bag or end up with very cold feet if I didn't due to the insulation being squashed by my feet pressing against the end of the bag. Just as a shorter bag is good for children, women and smaller men an XL bag is warmer for taller men. Although there is a difference between tall and big and that is volume. I can roll around in my bag as there is too much space in it. A small price to pay for warm feet and a good nights sleep.
