I'd go shoulder rig all the way.
Here are your best options:
http://www.epsaddlery.com/pc-96-25-1942-tanker-holster-5-12-to-8-38-barrels.aspxI love the El Paso rig. But after buying one of these I think I love it more better. The holster part of the rig unsnaps and can be used as a belt holster. Also allows additional holsters to be used with the existing shoulder rig. It is extremely comfortable and very well made. Norm is nice guy.
http://www.montanaholster.com/Travis