Barrel length for me would depend on your intended use as a "companion" handgun. I've had 4 ¾, 5 ½, and 7 ½ inch barrels. As you would imagine, shorter is easier to pack than longer, shootability often is up to you.
I will throw you a curve ball on your choice of SAA. Take a look at the no longer manufactured USFA SAA models, the ones finished by Turnbull. Fit and finish is superior, they look like the old ones, throats are correct diameter, very nice looking and shooting handguns that would be a fitting companion to your Shiloh.
Regards,
Manny
