Holster support and track record for the Holosun is minimal.
Olight has some (not top tier) holster support but a very mixed reputation. I wouldn't personally buy one.
Streamlight TLR7A and TLR7sub have the best track record and holster support for a small light. Seems the obvious choice.
There's still really only a few lights which have a track record and level of holster support I would consider acceptable, the TLR7, Streamlight TLR1, and Surefire X300.