For personal survival, remember the rule of 3's.
"You can survive 3 minutes without air, 3 hours without shelter, 3 days without water, and 3 weeks without food." So, here's how I would recommend looking at it:
- Shelter -- the 4runner will provide a lot of that, but a good sleeping bag, gloves, warm/dry coat, and stocking cap should go along. A pair of light rain pants over your shorts or trousers will also help a lot if you have to be out in bad weather. A stove and/or a way to make fire is a good idea. Everest climbers survive on hot tea. Just drinking hot water will help immensely in keeping your core temperature up.
- Water -- Figure a gallon/person/day in the desert, less in the mountains. In the mountains you can purify local water. Also, it's much better to drink un-purified water than to go without, unless you're stranded in an EPA Superfund site.
- Food -- Food is a comfort item, more than an absolute necessity. You can't starve to death in a week, but you can get uncomfortable, irritable, and make poor decisions if you're hungry.

Beyond that, take an Inreach or Spot satellite emergency communication device. Activate that and there's nowhere in the lower 48 where you're more than a few hours to a day or so (depending on weather) from rescue.