I need some help! I am a newbie looking for a good holster for my new S9. I inquired with the folks at Mitch Rosen who said they have the block for the "M" series, but not the "S". They also said if the "M" & "S" are the same, other than barrel length, they can make the holster. Does anyone know if the "M" & "S" are the same demensions except for the barrel length? Thanks!