A full size SAA whether Colt, Ruger, or copy, in .357 is a heavy gun. The smaller holes in barrel and cylinder leave a lot of extra iron in the .45 size parts.
My Single Six .38 conversion is a good deal handier. It would be handier still if the original purchaser had left it with the aluminum grip frame and hard rubber grips instead of steel and stag.
I think a Single Seven would be a good centerfire plinker and a set of dies would be a lot less expensive than custom sex change.