OWB carry in a custom leather holster of your chosen style or design would probably look best. Unfortunately, they tend to be expensive.
While this style might not match your normal wardrobe, check out some of the ideas in this thread:
I seldom need to "dress up", but when I do (and decide to OC), I carry in the nicest leather holster that I have for the "weapon of the day". Normally this is my Ruger Alaskan in a holster made by Sunrise Leather in Florida (check them out at sunriseleather.com.)
There are plenty of folks who do excellent leather work, but Sunrise happened to be who I found first. I paid $170 for the lined model, and it is by far the nicest holster I have ever owned. The picture is from their website, and it doesn't do the holster justice. It is not a fancy design like the Tucker models in the thread listed above, but is well made, and the quality shows. It fits close to the body, so it will work for CC with a cover garment, or as a nice OC dress holster. As an added bonus, it isn't too flashy to wear with jeans. Pick one that matches your taste and wardrobe. My $0.02.