if for a week, water is going to be the big thing, mabye some small snack bars in terms of food.
Your price range is going to dictate big time, I would say bed rools, and a light sleep bag for every one, and then your essentials.
Water/Food
Fire/shelter
Signaling/navagation
Medical
and the goodies
Every one should have a compass, and know how to use it. You can take a GPS. First aid kits, and every one should know how to use those as well. Radios for you all would be a nice touch, to keep in contact, ones that run on common batteries.
The knives and all that aren't going to be a big deal, the packs you carry all of this in are, a good pack will mean the difference in a situation from hell, maxpedidtion, kifaru, Northface, all the good names, and the bonus is you can allways find a good pack in your price range.
1.Water and food, purifacation tablets, A pot to boil in, and somw over bags allready labeld to know how much ater is in them.(most tabelts work for a certain amount of water, like one tablet for one liter or quarte)
2.Fire and shelter, you want some 550 rope, a folding saw, a knife and a 8X10 tarp.
3.Signal & navagation, every one should have a main compass, and a back up. If you can, everyone should have a gps, but atleast you should have one. A map of the area your in, and know how to use the compass. Glow sticks for every one, 4, 12 hour green glowsticks, a decent light, raovac has one for $15 called their outdoorsman model that is perfect for making multipul kits.
4. medical, everyone should have the knowledge to back up their kits, not the other way around. being able to improvise is the best thing, a kit by its self is useless if you dont know how to use it.
5. the goodies, its nice to bring some candies, maybe some energy bars. just little odds and ends that arent essential.
Aside from that, extra cloths, what ever medication you might need, you cells, some money, what ever you like for defense.