Gear and explanation:
1) Pistol: go withs something potent and reliable, but as light as possible...weight will be a concern when bugging out. Have magazines for no more than 20 rounds of ammo and no less than 14. This will give you enough firepower to deal with anything within reason. To reload quickly, have a magazine speed-loader on hand. Keep about 100 rounds of ammo on hand. Remember, this is for defense, not for some virtual WW3 scenario.
2) Knife: Go with a multi-tool in this instance. It'll provide tools, as well as the knives. Make sure to have a belt case so it's readily acessible.
3) Food/Water: Ignore filling, and go for outright nutrition. A blend of multi-vitamins and some high-calorie bars you can make at home, then vacuum pack will serve you well. I've seen some bar recipes where two bars is 2400 calories and about half the USRDA for nutritional content....a single multivitamin brings it into proper nutrition. the other advantage is that the pre-prepared bars have no prep-time, no need for cookware and no need for plates/utensils...less to carry. For water, keep a filter AND Iodine tabs on hand. Optionally carry some gatorade powder to add sparingly to water to make it more palatable. If you have to carry water, have 2-liter bottles for each person, but 5 gallon containers full of water for each person as well. The 2-liters are a compromise for if you have to leave on foot....follow a waterway and filter/Iodine/gatorade powder as needed.
4) medicine: cortisone creams, ibuprofin (and any other painkiller you may have legally), superglue (to close cuts), Hydrogen Peroxide/90% Isopropyl Alcohol, wraps, sterile pads, and "popsicle sticks" are all a must for a first aid kit.
5) misc supplies: Space blankets, signaling mirrors (get the good ones), reliable butane "jet" lighter with a refill cylinder, handheld CB radio, AM/FM radio to recieve information, cell phone with extra batteries (yes, have a replacable battery model, with all batteries at full charge, use only when requried to), playing cards (for those times you can't do anything but wait). Clothes (take plenty of socks), extra shoes, waterproof coat/overpants....the stuff that keeps you from getting sick or from having blistered feet.
The idea of bugging out is a worst case scenario, but is not an apocalyptic scenario....just view it as a "get the hell out of dodge" kit....what it will take to vacate your area without any uneeded stops, and enough foresight to handle the way some people react to bad events in the worst way possible.