Sorry, should have seen this last week. You don't need the RT Pro 6 hole rail mounted ones with a ULE vert body. The classic slide on ones work too. II Sports sells the light grey ones that slide over the body. Nicer ones exist somewhere out there too. I have a black one that has a small set screw to tighten it down into place on the body... thing is, it's currently in use with an armson sight on my PF mag.
People who are unfamiliar with occluded sights just don't get how great they are with vertical and power feed bodies. Most of the time I don't actually look at the sight but it's there when I've got the time to line up that one shot.