I strongly recommend the SIG with the DAK trigger system. Some of the models are called "SAS" - apparently that's the DAK trigger system and rounded ("dehorned") edges.
The advantage of a double-action trigger (like the revolvers you are used to) is safety. It's a fact of life; people sometimes forget Rule Three and they rest their fingers on the triggers. I know they shouldn't, but it is not enough to say "Serves 'em right" when somebody shoots their leg or their child. Most auto collisions are the fault of the driver, but that doesn't mean cars shouldn't be designed with anti-lock brakes, seat belts, and other safety features designed to be forgiving of driver error.
The advantage of single action pistols is that they can be shot very precisely. The disadvantage is that they are unforgiving of Rule Three violations. You so much as let your finger hover in the general neighborhood of the trigger, and a SA gun is going to go bang.
The current craze is pistols like the Glock, XD, etc. These have a trigger mechanism that is a little heavier than most single action autos, and a little longer than single action autos, but not as heavy or as long as DA revolvers. So, what you get is a pistol that is not all that easy to shoot accurately, but not all that forgiving of Rule Three violations. (Google "Glock" and "accidental," and read a few of the 83,000 hits.) To my mind, carrying a Glock/XD type gun is like carrying a 1911 with a lousy trigger and the thumb safety removed.
Back to the SIG DAK. It has similar weight of pull to the Glock/XD system (around 6-7 pounds), but the length of pull of the double action revolvers you are familiar with. It is long, but smooth. It is much more forgiving of Rule Three violations than SA's or Glocks, but can be shot with precision much like the PPC and Bianchi Cup revolvers with their super-light, super-smooth triggers.
The only drawback is that they are pricey, like 800-900 dollars. Still well worth it, in my opinion. At least try one out in the store.