The advice you have gotten is solid the only thing I'd add is that if you are new to using scoped handguns and your shots will be under 100 yds then the 2x will give you faster target aquisition but the 4x will be more versatile with practice and like Gary said the other option which adds even more versatility is the 2.5-8 and Leupold in my opinion is the best glass you can buy, it is more compact and lighter than the burris and has a better performance record but depending on your budget dropping down to the Burris, Nikon or Bushnell isn't a bad thing as they are all good scopes but as I've said numerous times the Leupold is the best but you pay for what you get.

I won't be wronged. I won't be insulted. I won't be laid a-hand on. I don't do these things to other people, and I require the same from them. John Wayne-The Shootist