Backpack or equivalent: Probably the most important piece of gear I will need - except for the shoes.  I need a lightweight pack with about a 30 litre capacity that is suitable for running in extreme temperatures.  Initially I was looking at the camelbak as water is carried internally, but the information I have gleaned suggests that this is not a good idea.  Weight of course is everything, I need the filled backpack etc to be less than 10kg total.

The best one seems to be the Aarn 30 litre (around £80) but it is out of stock as far as I can tell.  Other options are the OMM Marathon Classic and the Inov8 range.  They all have their pros and cons.  Raidlight Runner R Light 30L (RRP £54.97)  OMM Classic (£49.50) and the Inov8 Pro 30 (£49.50)

Supplier: Likeys, Hike-Lite and Outdoor Warehouse