This has nothing to do with camera gear, but...

I'm not sure what kind of condition you are in physically, Wayne. If you're going to embark on any type of walking with a 30 lbs. backpack, you should really consider doing serious ab and back exercises. I agree that the backpack should be a really good fit, but you will still be hurting if you're not in shape. If you have back problems (most people do) then it will be even worse. There is nothing more inconvenient than having back pains while trying to shoot, etc. Also, make sure you wear socks designed for hiking. You don't want to deal with blisters either.