The rail Aj posted is what I am using
One mod you might want it a thumb screw for the sizer lock, to be able to change on the fly. And not have to hear complaints about someone saying How I'm turning the FPS up on the field.
I used vm68 strip screws and didn't need the cut the length. I haven't tried yet but I do think a cci phantom frame screw moth look and work better.
I don't know if you can see it? but the rail is ramped. Maybe that's why I don't need a adjustable riser. Also I'm going to see what I can do as far as making a adjustable riser that suits our needs better. But money and time is a issue for me rightnow. So when I can I'll let ya know.