Mine is Police related. Safariland makes the "SLS" holster for the GP(686). They make the drop leg option for it.
I already had the holster on a belt loop so I just bought the drop leg part and swapped it on.
The holster is designed for Poilice duty so it's hard laminate but they last a long time. The SLS takes some getting used to if you are used to thumb breaks but it's an option.
I would think the nylon "Tactical" types from Eagle or Blackhawk could work as well.