To become proficient with pistols you need a pistol.
Besides I cannot fire a shotgun w/o my right arm going dead due physiology. (Weird I know, but true)
Fair enough, but there are plenty of good instructional classes out there offered at most reputable gun ranges that can teach you to at least get started on the path to firearms proficiency. Just understand that a handgun, any caliber, will penetrate walls with little to no problem. If you're going to take a shot at someone in your house, you best be aware of the foreground and background of your target, because when you miss, you're bullet will keep going until it finds something.
Forgive me if I sound a little preachy, but responsible firearm ownership is a pet peeve of mine. I will continue to beat this dead horse, but a handgun is a poor choice of weapon for home defense if the user is not completely confident with its use. Obviously, this can be mitigated depending on where you live and who you live with. If you live by yourself and have no neighbors for 1 mile in all directions, fire away. If you have roommates, they better know how to react as well if you plan on defending your home with a pistol. When someone breaks in to your house, chaos ensues, panicked roommates in the next room are behind that wall your bullet's about to go through. Your neighbor, asleep in his bed, is potentially only separated by 2 walls from the business end of your pistol.
Pistol calibers FAIL to expand when hitting light targets like drywall. Most various rifle calibers and shotgun rounds are not as prone to overpenetration.
http://ammo.ar15.com/project/Self_Defense_Ammo_FAQ/index.htm#OVERPENETRATIONStopping power is also a huge myth. No bullet is powerful enough to knock a person back. People drop when they get shot out of shock, pain, injury, or death. If a bullet carried enough energy to knock a person back, like in the movies, then it would knock over the person FIRING the gun too. Newton's third law is pretty clear on this...
Here's some ballistics gel data. Notice the 9mm wound is slightly smaller than the .40 S&W, or .45 ACP. Now transpose those wound patterns on to someone's chest or face, and you'll notice the caliber doesn't matter when it comes to 'stopping power.' You put that wound in a big man's chest, he's just as dead from a little bullet.