I'm in Kansas City. I think Missouri is one of the worst places to be in the summer. Looking at the weather charts it looks like north Florida would actually be cooler in the summer than where I am now if you consider the heat index.
With my anti-social tendencies I wouldn't consider anything less than 3 acres or so. Preferably at least 20 acres. I love trees also, so when i get something it will be entirely or mostly wooded. I've seen some places for sale with 20 acres and a livable house for under 100,000.