Hi John, I currently have an 8x10 triple extension "Tackyhara" that I use exclusively for outdoor work and I've carried it in a Black Wolfe "Cedar Breaks" 90 litre backpack pack with day pack attached. I have a polystyrene safety cell that holds the camera and lens, light meter, cable releases loupe etc, that goes in the main section and my 10 film holders go in the attached day pack. I carry my Manfrotto 075 tripod with three way head in my hand as I walk. I have carried all this for up to 15 km's through the Otways, up hill and down dale, whether there has been a track to follow or not. I am, however, going to get a new, lighter, tripod and, after discussion with people on the LFF forum, have decided on a Fiesol CT3471 4 section tripod from Really Big Cameras that I will attach my three way head to. At the moment these tripods (carbon fibre) are $319 USD which is quite reasonable, and they are fairly light as well. You can get the back pack from Anaconda, if one exists in WA and just google Really Big Cameras for their website. Good luck with your decision.
Mike