Ok I decided to return to this endevour and compile a spreadsheet of all the lightweight packs that are readily available in the UK that can carry heavy loads comfortably. If anyone interested
you can view and even comment on it here
it clearly lists all the attributes for easy decision-making.
At the moment the Lightwave ultrahike 60 or their wildtrek 60 seem to be the two best lightweight packs that can handle heavy loads (what's the differences besides the little extra weight of the wildtrek, anyone know??)
I also like the crux ak47 because I want something that is
just big enough for what I'll be taking because I find it much easier to pack the heavier items at the top of the pack where most men's centre of mass is located (opposite for women) which I find helps enormously with load carrying comfort, however without access to an ak47 I cannot be sure if it's 47 litres would be enough! If anyone near Nottingham has one please let me know!
Thanks for the Aiguille reccomendation, I've always heard good things about them but never came across one, at £100 it's certainly a viable option. Anyone know how Aiguille stack up against the other manufacturers? What kind of frame and suspension technology goes in to their packs?