Have you considered just replacing the 512 with another RDS? That would allow you to keep the magnifier and possibly keep the overall price down. Given how chunky EoTechs are, a lower profile RDS might give you more clearance. I imagine you might be able to find a used Aimpoint for under $500. I've heard good things about the Bushnell TRS-25 and the price is definitely right. There appears to be options with the mounting screw on the right side.
I ran a 1x4 with a burris mount that worked well. Only problem i had was height over bore for 3 gun, the close in stuff was really hard to figure out my drop.
How does the Primary Arms ACSS compare to the Vortex Strike Eagle?
Moe