I have a number of airguns and have been hunting for many years with them. Yes, there are air guns that can reach out to 100yds, and quite accurately. The Career 707 is a fine precharged airgun. This gun comes in .177,.20,.22,.25 and 9mm!
To see what airguns are really capable of, I'd suggest that you pick up a copy of Airgun Illustrated Magazine. All the info that you need can be found in there. The new issue is out now, and Ted Nugent is on the cover!
Also, it sounds like the airgun that you're looking for would be a Beeman R-9 (a spring airgun). These guns are great, and there are alot of after market things for them. They have adjustable triggers, Beech stocks and good bluing with match grade barrels.
Don't forget that although velocity is important, hitting the target is the name of the game. you'll find that the more velocity that a spring gun has, the more it vibrates and kicks. Yes, airguns do kick, not like a firearm mind you, but with a two way recoil.
The airgun will first come back into your shoulder after the trigger is pulled, then it learches foward from the piston rebounding off the air cushion that is created by the pellet in the breech. A spring airgun will last for literally thousands of rounds with little maintenence.
Pre charged guns are more costly and require a scuba tank or a special pump and filling adaptors. I would suggest a good spring gun to start, and then moving up if you like the sport.
The Crow Magnum is a gas spring gun that has , what is essentially, an airshock, for its power source. The "airshock" or "airpiston" is filled with air and then put into the gun at the factory. The air takes the place of the spring, which means you don't have to worry about spring wear. But, sometimes the seal on the air piston will fail, which then requires an airgunsmith to repair it.
Like I said, check out the Airgun Illustrated Magazine, and if anyone needs anymore help just ask. Dante'