Like JTQ, I can recommend the Safepacker, from The Wilderness dot com. It can be worn on the belt, like a belt holster, or on a strap/sling, like a shoulder bag, which, is essence, creates a shoulder holster. It can be fastened onto a pack. It can be hand-carried, with or without a wrist strap. An older Safepacker, found on evil-bay, may not accommodate a weapon-mounted light, but the newer ones will. Be sure to take the extra length of one's preferred light into account, when ordering. My Safepacker, in the Government +1" size, carries a G34 with mounted Surefire light quite well. (The G34 is the Glock designed closest in dimensions to a Colt Government Model.) I have also used it to carry full-sized 1911 pistols, though mine have no accessory rails, and G19 and G19 pistols, with and without lights mounted. This is my usual dog-walking holster.
JM Custom Kydex makes true art in Kydex, and is known for being very communicative with customers. My JMCK holsters were not made to accommodate lights, but judging by some photos, JMCK has learned how to make a holster that accommodates a pistol with an WML, without any excess mass and bulk.
DSG Holsters uses a kydex-like* thermo-formed plastic, for a variety of pistols with lights. These are bulkier holsters, with more material than JMCK, covering a larger footprint, but as concealed carry is not part of your equation, the DSG Alpha should work well.
The Raven Concealment Phantom is not quite as artfully-crafted as JM Custom Kydex holsters, but is quite close. I have a lefty Phantom for the G19, that accomodates X200/X300 lights.
The Bawidamann Gotham is an unusual IWB holster, that locks onto a pistol-mounted X300U Surefire light, and has enough clearance to accommodate multiple pistol makes and models. Quality of construction and materials appears superb, but with one very significant caveat: bulkiness/mass. I am considerijg mounting my Gotham inside a pack or bag, rather than using it as a inside-waistand holster.
*Kydex is not necessarily better than the several other thermo-formed plastics used for making holsters and sheaths.