Wood stoves and fireplace inserts with flat surface tops make excellent stovetops. If you have a wood burning fireplace, think about buying an insert that you can use for emergency cooking.
One of the advantages of using a wood burning stove to cook food is that you do not have to cook in a hurry. If you are using the stove for heat and light, you can cook or simmer food for hours on top of it.
Propane Stove and Oven
You can buy economical propane stoves. You can also purchase propane ovens. You may already use propane with your barbecue. It can be a little tricky to store propane, but generally it is safe. Just be sure fumes do not build up where you store it
Charcoal and Dutch Ovens
Charcoal can be stored indefinitely. You will need a Dutch Oven to cook using charcoal. Don't confuse cast iron pots with Dutch Ovens. Dutch ovens are flat on the top so that you can place briquettes on the lid. The bottom of a Dutch Oven has feet, so the you can also place the briquettes below the oven. See Cooking with Charcoal.
It can be tricky to regulate the temperature in a Dutch Oven. In general it takes 24 briquettes (12 on top and 12 on the bottom) to generate 350 degrees of heat. They should last about an hour on a warm day.
Cooking with a Dutch oven is tricky. It is both a science and an art. Watch some videos to perfect this skill.
The Volcano Stove
Another great option is to purchase a volcano stove. This is an extremely versatile stove. You can cook with many types of fuel, including charcoal, wood and propane.