scrum, you'll definitely want to shoot before you buy. If you can, rent a 19, 23, 29, 30, 36...heh, I'd better stop spending your money, but you get the idea.
The 23 is great as a carry gun and probably one of the best all-around practical pistols on the planet. It's small enough to conceal and large enough to handle easily. It's identical to the 19 except that it has ~20% more horsepower and two rounds less capacity. I've had two and they were both great. The 19 is worth considering, too, as it's easier to handle and cheaper to feed.
The 29, 30, and 36 are also worth a look if you want something a little more substantial. I'm getting pretty partial to my 29. It's the tupperware equivalent of 11 surprisingly controllable rounds of .41 magnum and that works for me.
As for holsters, I keep an IWB that either snaps or clips on and a OWB paddle for my carry guns. That covers pretty much everything except for swim trunks and a tank top. Galco's my brand, but there are a LOT of good names out there these days. Buy from the shop that will let you try on a rig to see how it feels. You'll save yourself a box full of expensive leather that way.
Have fun shopping and let us know what you go with.