GapAdvice.org - The Independent Gap Year Advisors

You will need to think carefully about what clothes and equipment you need to take with you.  Bear in mind that many things are cheaper to get overseas and there is a tendency to take too much.  Look at these sites for suggestions on such items as rucksacks, sleeping bags, clothes, footwear and medical kit:  

Travel Equipment Specialists

www.travelwithcare.com : offering 10% discount.

Also:

www.nomadtravel.co.uk

www.gapyeartravelstore.com