This is going to be a tall order to fill as any advice given on what leather IWB holster will fit two totally different guns is going to be speculation to some degree.
Typically, leather holsters are molded to the gun they are for. While there is some level of swap-ability between similar guns, say a P-10 and a 1911 Commander sized gun etc. Going from a 1911 to Ruger may or may not have the desired fit.
Unless you're looking at something like the NRA Slide Holster, there aren't too many leather "one size fits most" options.
What exactly is your budget?