Revised my BOB along the lines of some cold weather kit, as i'm sure if i get too hot i can take stuff off but if it gets too cold i can't put on what i don't have !
After some research and i quote " Sometimes, any sort of layering system simply isn’t warm enough. After all, there is a limit to the number of layers that it is possible to wear before normal movement becomes severely constricted. So in deep cold conditions, or in chilly weather where you are likely to remain static for any length of time, a heavily insulated garment – known as a duvet jacket – is useful. Duvet jackets are normally too warm to be worn whilst active, except in situations such as high-altitude mountaineering. More usually, they are worn during rest breaks. Lighterweight, pullover-style versions are also available. These are perfect for wearing in less extreme conditions, and are a warmer and lighter alternative to a spare mid-layer."
http://www.cotswoldoutdoor.com/data_doc ... eather.htm
After some time on evilbay i opted for a Norwegian army top and a Snugpak softie.