Have you ever heard of a pelican case? its a plastic case thats very durable (water proof, dust proof, and it provides great anti-shock resistance)
Check them out at http://www.pelican.com
they have a lot of great videos at their website
if you want something for just the body i would recommend a case this size (1200, but there are smaller and larger cases available) , it would also accommodate a lens attached to the body. I do quite a bit of backpacking myself and i plan to purchase one of these to throw in my pack. hope this helps...