I understand the differences between DAO, DA, SA/DA... but don't know what I would consider best for concealed carry as they all have their benefits.
Keep in mind that a majority of the DA firearms will not have a manual safety. IMO, they are one of the best available for CC due to the consistent trigger pull (this coming from a DA/SA type of guy). I always thought I wanted a manual safety for each of my firearms... then I bought a Kahr.
As mentioned though, your choices are all over the place. If you are set on IWB carry, then I would go with the largest handgun that you could comfortably carry (maybe a small 1911). If you are open to .380, then maybe you are considering pocket carry as well. For those, you will be a little more limited when looking for something with a manual safety. Maybe the PM9 w/safety, although I think those can be pretty pricey.
I think once you get to a shop, you will have a better idea. Maybe you could swing by your LGS and come up with a list of guns that you are considering. Since you've shot handguns in the past, you might want to pick out a specific caliber and then go from there. Right now you've got .380/9mm/.40/.45, so I think you've covered just about everything.