This is just my opinion. I am sure there are exceptions. By and large DeSantis holsters are the best value for the money.
Really, you are over thinking your holster selection. If you have love handles carrying IWB isn't going to be fun unless you are prepared to appendix carry. I have a box full of leather holsters I put a lot of thought into buying. Each purchase was attempt to carry a gun in a way that my body isn't built to do. I finally wised up and realized I have two choices when I carry a gun. I can either wear a paddle holster and dress around it or I can put the gun in my pocket. There is a third choice appendix carry IWB. I don't like the idea of a gun pointing at my junk and the gun really spoils the mood when my wife is frisky.
Here is my G19 in a Desantis Pocket Tuk. The G19 is close to the same length as your security six. The pocket tuk also has a clip for IWB carry. For $15 the Pocket Tuk is a very versatile holster. The soft Tuk similar to the pocket Tuk but it is a little more compact.