Keep $1000 in small bills... The ATM won't work and people won't take checks, cards or big bills... A couple weeks worth of water...a motorcycle with extra gas in cans or old plastic coke bottles...or a fast bicycle...for "shopping"... Gas may stop being pumped... and food hoarding will clear the shelves... as financing for new deliveries may collapse...
Remember its not the 'shortage' its the hoarding that gets you...!
A months worth of canned food...don't forget the can opener...! Enough Beer and Hard Liquor...for personal use and to trade. Charcoal and wood for burning...Nat gas may stop flowing... Some propane and a stove... A lantern and lots of candles and matches... A trap for catching rain water... Hand operated gizmos because the electric ones will be useless... A cross cut saw for wood...
A battery radio or TV....with lots of batteries... Shot gun...long gun...ammo... barbed wire...and a mean dog...two or more even better...but you have to feed them...
Small towns will be safer than large cities or isolated camps...a militia can be formed to protect small towns...and to pool resources...