If you want to stick with an auto, check out one of the smaller used 3rd gen S&W autos. You should be able to easily conceal a 3913. There are a lot of fans of the 6906 (if you don't think double stack it too bulky). There are lots of varients and different calibers too - CS9, 4013, 4513, the DOA versions (-53), the blue slide versions (-14), Performance Center guns, etc.
I can also recomment the steel Kahrs. I have an original E9, the economy version of the K9, and it has performed very well. I little heavy because it is all steel.