Alas sir, they don't exist. Only place I've seen them is attatched to ones on eBay. I contacted JPS Trading on there to ask about them and they said they can't get them, so I think those ones are custom fabbed.
If you can get your hands on a Apexi one, you can have the 2 holes milled out to accept the Blitz bolts from underneath. I did this with mine and it worked perfectly. Apexi mounting and aperture holes are dead on exact sizes to the Blitz Bov.
