Any reliable compact firearm will work. Just practice, practice, practice. I have the SW Model 19 .357, 640-1 in .357 then Glocks 23, 24, 27, and the Sig 229 in .40 I would feel comfortable with any of them. Well the Glock 24 is too big for concealed work. Its not the handgun its the owners skill level. You can name a hundred handgun variations that would work and work well. You really only need one and you have to have a high skill level. You said you had the P-7, if you like it, leave it go at that. You will find none better. The small glocks like the 27 or 26, with the pinky extensions on the magazine are awesome guns. An airweight J-frame .38 in your pocket beats the crap out of nothing too. While I decided on .40's and the Winchester 155 slivertip, I am sick of the caliber debates. 38 special up .357, 9mm, 40, through 45 are all just fine if you put the rounds where they count. If you can shoot it fast and accurate, go with it.