Just to throw out another option, you might consider a Kahr PM40. Slim, light, and an all around good gun. Of course, my favorite for all day every day carry in any condition is S&W J-frame revolver.
I carry the Walther PPS in 40S&W year round and love it. The Taurus 740 Slim wasn't out when I decided to start carrying, so I don't know much about it but it has very simular dimensions to the Walther or the Kahr at a much better price.
My year round carry is my glock 27 with crossbreed belt and milt sparks versa max II holster. With a good belt and holster you will forget you even have the G27.
I just picked up a Beretta PX4 subcompact earlier this month and it has become my every day carry and favorite pistol. I have Crossbreed holster, but find I like appendix carry with a Looper holster better. Mine is 9mm but it is available in .40. It is about the same size as a G27 or xd subcompact. Under $500 at both Academy and SportsWorld in Tulsa.