I'm not sure there is such a thing as a IWB-SOB these days. For a number of years, the OWB-SOB was a popular rig, in particular, the Galco SOB.
I used an SOB for a number of years as a firearms sales person. I found it quite easy to conceal well, comfortable and easy to access in all situations save one... driving a vehicle. Bear in mind that both of the guns I carried in SOBs were not exactly small or light... a 5" SS 1911 and a HK P7M8.
If you want to try IWB-SOB, you have to consider what angle you want the gun butt to be presented and if the design of the holster will accommodate you. If you are right handed, you may end up with a left handed holster to achieve the desired result.
Shoulder Drive Nicholson Club