It all depends on the type of environment you are surviving in. Canada woods is different from Arizona desert. Changing identities and moving to New Mexico would be different from sailing away on a boat and living off it. Are you concerned with weapons for hunting or protection? How far do you want to travel? I wasn't able to get 2 miles with what I packed on one of my Canadian backcountry trips and had to stop by a post office and mail 8 lbs of stuff back. What season are you going in?
And if you can't setup a base camp, or are worried about people seeing a fire, then it changes as well.
And I would use a solar still or UV light for water purification. I take one gallon jugs of water with me normally.
If I were shopping for a backpack, I would want a separate waterproof compartment for my tent and poles to get stuffed into. Ex Officio clothes
http://www.exofficio.com/, 1 gal water, some food, sleeping bag, maps, knife, and a survival book. I would also consider taking my mountain bike to travel faster and further.