Some thoughts:
1. Get to know your neighbors. Not just on either side of you but up and down the street and behind you. They might be sources of help or sources of misery, but it's good to know in advance.

2. Buy the truck. You can get one cheap now and gas prices are coming down. The usefulness of a truck is blows away SUV and regular cars.

3. Get a dog.

4. You siad you plan on being in the house for two years. Than what happpens? Do you know if you move into a another house or will your return to the city? That affects what long-term preps you make.

5. Water. Izzy suggested a well but is that an option on a barrier island? Aren't they just a big pile of sand? The Sportsman's Guide sells a hand-pumped reverse-osmosis desalinator for life rafts for under $800. It might be something to think about if you have the money.

6. Communication - ham radio or else just hope the phone lines/cell phones/text messaging works. Then again, a carrier pigeon might work.

-Blast