I'll second the suggestion that along with the handgun, you purchase a *good* leather or kydex holster from a major maker, a good leather or kydex magazine carrier or two (I like the Galco DMC), a good reserve of magazines, plenty of practice and carry ammunition, tritium sights (I like Trijicon, different color front and rear), and a good weapon light (either mountable for bedside use, if your handgun supports it, or handheld and carry-able), a good cleaning kit, and range time.
Good accessories together will cost as much as a good handgun themselves, so consider that in your budgeting.