I would reccomend a revolver also. A 357 will give you the all around round. You can load 38's if you want a lighter load or for the wife.
Dan Wesson revolvers have interchangable barrels, you can get a used one for very little (gunbroker.com)
I have the 2.5,4 ,6 and 8 inch barrels.
I carry a Springfield 1911 A! (Full size) in .45. I would reccomend any quality 1911.
I also own a Glock 22 (.40) its light, good power, reliable. Lots of options.
i would choose the 1911 over the Glock, but thats my choice.
I also own a .380, but if you want a gun you can carry and mabey compete in IDPA, go 9mm and bigger. You will be happier with the bigger round.
The average shootout last 3 rounds, dont worry about capacity (A revolver will do fine) go rent some at a range and see what feels the best.