Just to throw in my two cents worth, I use Leupold rifle scopes (atop TC Contender) for the eye relief. Have a Burrise 3-12x32 that's phenomenal, will focus all the way to 500 yards, but it's hard to hold that small a pistol scope steady. Really great glass and quality. I have a few Leupold Vari-X II scopes also, love them. They're 4-12x 40s.
Scope thought: The higher the magnification you use on an adjustable scope, the closer you'll have to hold it to your face.
For most applications, a 10 power scope works, a 12 power good quality will easily take on 300 to 500 meters, and everything else is comfort.