I would want an underground storage area such as a root cellar or basement. Living in tornado alley, betting on anything above ground surviving in the event of a disaster is foolish. I would also like to have a 50 watt dual band amateur radio hooked up to a car battery. Food/ammo/weapons/medical supplies all seem relatively straight forward as they can be kept for years without any work on your part.
Power and water are the tricky ones in my mind. In my area, disruption of utilities usually coincidences with ice storms in winter. This means that travel is a non-starter, and a cistern or rainwater collection system isn't too helpful. My preferred method is to keep empty 2-Liter bottles, clean them out, and fill them with water before stacking them in my tornado shelter area. I also like to keep a supply of chlorine tablets on hand (tastes better than iodine). For electrical power I think the best bet is a generator with enough juice to run your essential things. Yet generators are limited to the amount of fuel you have on hand, and that has to be rotated regularly.
Sounds like an interesting project, good luck!