Air Rifle Suggestions?

[Razor]

For as much wide open space as Colorado's front range provides, there are damned few decent ranges to frequent to teach my oldest son how to shoot a .22 rifle. So, I'm thinking my best bet is to buy a good air rifle and take advantage of our 2 acre backyard to teach him the fundamentals. When its not being used as a teaching tool, I may pick it up now and then to take care of a growing cottontail problem on my front yard, something the neighbors would really look down upon were I to use a .22. While I started out with a single pump 'lever action' Daisy as a kid, I'd like to pick up something a bit higher quality, especially with some basic but solid sights. I'm not looking to enter competitions, so a high-end target rifle isn't necessary. I'd like it to have enough 'umph' to take care of a hipity-hopity without causing undue suffering, but still be a good kid-teaching gun, if possible. Any suggestions?