Since I have the CZ p07 I'll comment on that as it meets all your requirements at a sub $500 price. Even more interesting to you might be the fact that if you try da/sa and decide it is as bad as some people say, the cz comes with parts to make it a single action only (and with a nice trigger to boot). Also the grip is significantly smaller than many other doublestacks (almost too small for my hands), and still holds 16 + 1 to boot. Only downside is the slide is a little on the thick side for concealed carry. Other downside is the magazines are on the pricey side, but not out of line with any of the others suggested here and readily available from the company.