shotgun,
most pistols that shoot a .40S&W will also allow you to shoot a .357sig. For instance, my USPc in .40 only needs a barrel change, it can even use the same mags as the .40. The reason this is possible is because the cartridge cases are exactly the same for the .357SIG and the .40S&W.
This isn't true with the 9mm and other cals. Now you're getting into different case sizes, recoils, etc, so more parts have to be changed. Theoretically it's possible, but it's not something I'd want to do as a new shooter, and without an experience armorer right there to watch me do it and check my work.
The guy who taught me how to shoot always recommended that even if you buy a centerfire pistol to start (something good for CCW, 9mm and up), that you buy a .22LR pistol to go with. You can use the same techniques on the .22LR to practice shooting, at far less cost, and removing the flinch from the equation.
I understand wanting the P2000SK for CCW, except I was wondering if something along the lines of a USPc or P2000 would work just as well. Most reviews that I've read show that the issues in concealing a firearm come more from the width of the pistol then the length. Many people on this site carry a full size 1911 as their daily carry. Adding barrel length gets you a bunch of advantages, including a longer site length, a faster velocity from the bullet, and a more accurate gun.
Anyway, my suggestion to you, buy a pistol that is slightly less money, I know a USPc was about $100 less for me then a P2000 would have been, and also pick up a decent .22LR. I got a Ruger 22/45 w/ a 5.5" barrel. You can see both my pistols at
this thread.
Hope all this helps dude. I definately don't know it all, but I do try.
--Jim
BTW - I don't love or hate Glock, I respect them, and calling them tupperware is just a joke, cuz my USP is half polymer too
