I've found over the years the bed frame is the limiting factor more than the actual holster. For quite some time I had an RDR kydex holster for my G17L with light mounted to the headboard. It was a sleigh bed so there was a dead space between the area where the mattress was and the wall. I never mounted the belt loops on the holster shell, instead using cable ties and the rivet holes to mount the holster to the bed. The benefit of the sleigh bed was this left it out of sight to anyone walking in the room, but still quick to get to when in bed.

These days I've become a fan of mounting a QLS receiver plate to a fixed location and then I can use any of my ALS holsters (or my T-Rex Ragnarok if using a suppressed pistol) that has a QLS fork. But again, the design of the bed frame, and material (wood, pressed board, metal, etc.) will be something to consider.