If you're in a rural area where muzzle blast noise isn't likely to cause the neighbors to call the law, why not go with a 223?
223 ammo is inexpensive and easy to find, think Wal-Mart, compared to either the .22 MAG or 22 Hornet.
When I lived out in the country, I kept a .22 MAG and a 223 on pegs over the back door, the .22 MAG for shooting foxes and feral cats/dogs that were close in and a 223 for coyotes that were farther out.
