Haven't seen many at all. Who is making them?

http://www.508holsters.com/

Local guy here. Makes great stuff. The apl-c one is called the "torch." I don't have one yet but from what I've heard, no complaints.

Tier 1 concealment makes them along with KT Mech

I personally have a Tier 1 Xiphos that I've been relatively happy with. I wish it had slightly more retention, however with the APLC the head of the light doesn't really give anything to grab onto. I haven't had any issues though with the firearm becoming loose while carrying though

I don't have any experience using the KT Mech holster however will be ordering an OWB from them here soon.

Tier One Concealed Xiphos

KT Mech

You thinking of IWB/AIWB or OWB?  I know T-rex has included them in the lineup.

I have one IWB and one OWB G19 aplc holster from T.Rex Arms. I highly recommend them.