I've used the Latigo for years. Recently I got a Montana sling and feel it's the best yet. It's super simple and sometimes simple is best.
This sling was developed by Scenarshooter (Pat) and he should know a thing or two about shooting and slings.
Regarding the 26 Nosler, I think it will do well. It may well perform with or better than the .264WM and hopefully, it won't be a finicky round. With new powders now available, like RL-33, this round has come at the right time.
I have a good bud who's looking to pick up a shot out M-700 7RM. That action should be a good one to convert to 26 Nosler. It may need a box mag with windows like the RUM family. These windows allow more room for wide body cases to fit under the rails.
See this link on the .404J.
http://www.24hourcampfire.com/ubbthreads/ubbthreads.php/topics/7846376/2DF