Here is my "light" carry rig. It is what I wear when my clothing prohibits me from carrying my Hi-Power. So far, this means when I'm in a suit or in shorts. The pistol is an FEG PA-63, which is a clone of a Walther PPK. It's a fairly compact gun, chambered in 9mm Makarov (9x18). The Makarov round has enough to it that I don't feel like I'm wearing an tiny underpowered firearm around. Ballistically, it's somewhere between a .380 and a 9mm. The gun itself is aluminum-framed and very light at 21 ounces. It's somewhat snappy, due to its weight, but still lots of fun to shoot. Since it's a surplus gun from eastern Europe, they're pretty cheap. AIM Surplus carries them for $129.95 right now, and include 2 magazines. The downside is ammo availability. The only quality defensive ammo that seems to be available in 9x18 is Hornady XTP. Federal used to make some, but seems to have discontinued a couple of years back. The XTP is pretty widely available nowadays, and it's usually available at Cabela's when I go there. Range ammo is pretty easy to come by. Most gun shops will have some sort for FMJ in this caliber, and a place like Cabela's has S&B for a decent price. You'll find a pretty big selection online. I favor S&B because it's relatively cheap and brass-cased. The WWB in this caliber is actually manufactured for Winchester by S&B. As far as I can tell, Academy and Wal-Mart do not carry any 9x18. Here's what it looks like, along with my carry rig. I use a Bianchi Professional 100 IWB holster.
I've found that when fed brass-cased ammo, the gun is flawless in operation. I started out shooting steel-cased Silver Bear, and had feeding issues. This was mostly with the JHP ammo, as friction from the steel cases would drag the top round (with the most spring tension) on the magazine lips and turn down the tip as it was feeding, causing the hollow point tip to catch on the front of the magazine and fail to feed. I've put probably 1400 rounds through the gun now, and tested with a leftover box of the Silver Bear JHP stuff this past Saturday, and found that these rounds no longer fail to feed. It could be that the gun and magazines have polished themselves up since I started using it. Bottom line, if you feed the gun brass, it should be fine and dandy. It has established itself as reliable for me, and I trust it as my carry when needed.
(edited to clarify ammo information)