9mm leaves you undergunned? hardly. It's not on the light side, i don't care what anyone says. Sure a .40 or .45 has more behind it, but with today's defense rounds a 9mm is pretty effective if you are trained.

i would suggest the Springfeild XD9. i have one, and its quite the firearm for the price. over 2300 rounds on mine without a single malfunction using Winny White box. This gun is a little big to carry so i have a 380 for that. But you have to decide if you are going to carry or not and let that be your guide. If you are just going to be plinking, get a .22LR pistol and shot 550 rounds for $12 instead of 50 rounds for $15 (9mm) or $22 for .40 cal. If you are looking for a defense gun there are so many choices but they all matter if you are going to carry. If there is any chance you will get your CCW and you don't want to buy a bunch of guns, you could look at Kahr, Bersa, or a revolver which should be 9mm or bigger yet smaller framed. Just go with what fits your hand best.