I can only speak from experience...
If you plan on going leather, I can't recommend Dwayne anymore than what has been said and shown. I have some of his Randals and have had many more of his other styles. The work Dwayne does is top notch. Dwayne is a true artist with the carvings and inlays he does. I really believe that there's not much Dwayne couldn't bring to life in leather. Right now I have two more on order....not even sure how many that brings me up too.
If kydex is your thing, than you'll have to decide on what type you're looking for. Fold over jobs, small and discreet, I would have to say Buy Brown is the way to go...his Kydex is freakingass thick and tough as nails. But David does tend to design his sheaths to grab the blade rather than the handle. On some knives I prefer this...he's able to make the sheath smaller this way and it's makes concealment much easier. I've ordered several if not more from David and not had a single complaint on his work.
If you have a safe queen satin and size of sheath (bulk) isn't an issue than Brian Wagner is the way to go. Brian is famous for the "snap" sound his sheaths make when they lock onto the handles. They don't touch the blade much at all. I have one for my LEFBM and the bad boy is rock solid on retention, and has little to no contact of the satin finish blade. I'm not aware of Brian making fold overs, but he could answer that better than me. I currently have two sheaths coming from him. AD and a MrS sheath.
I strongly suggest you contact any of them and let them know what you're looking for. All three are wonderful guys to work with and I'm sure they can do pretty much whatever you might need. They have the most experience with Busses that I'm aware of.
Hope this helps!