>>9607800Respirator:
http://www.amazon.com/3M-Cartridge-Full-Facepiece-Respirator-Facepiece/dp/B001RTG84A/ref=sr_1_9?ie=UTF8&qid=1330288225&sr=8-9
You can get a gun via private sale if you're over 18; go check
armslist.com in your area and see if any private parties are selling.
You will need a contingency plan, let friends know where you are going, and have them call for help if you are not back in, say, 24 hours. Carry more food and water than you think you need, you could get trapped somewhere and have to survive for a bit.
3-day emergency ration bar:
http://www.amazon.com/Datrex-2400-Emergency-Food-Bar/dp/B001CS7MBE/ref=sr_1_1?ie=UTF8&qid=1330288564&sr=8-1
Carry a couple religious symbols and know a set of prayers for each, go with a cross, Jewish star, and something else. Flashlights, make sure they are LED powered, over 80 lumens of brightness, and have extra batteries for them.
Carry a spear point fixed blade knife, and a pole, fashion the knife to the end of the pole to make a spear, it might not seem useful for defense, but it will help you keep some distance from whatever is at the other end.
Good luck, I hope you get some awesome pics out of this.
