You can fit 4 REV 10, however you cannot fit them using the MC adapters in the factory locations. As they moved them closer together. So you can put a pair of REV 10 using the clamps on the pipe. And another set on the factory adapters. Or the other set on clamps and not use the factory "disc" mounts at all. We have had a lot of guys do this when running PRO 485 and now with the new REV 410.\ Some have added little led pods to the disc mounts for some down lights to re purpose them and not have it look like something is missing.
You can fit 4 REV 8 with MC adapters all in the factory locations. The REV 8 is the smallest true 8 inch HLCD on the market so if you are worried about headroom, i would go that route. Using a REV 8X mount direct bolted to the MC Adapters and you will be nice and close up to the tower.
You can also use the REV 8 SC swivel clamps and take the removable bases off and bolt those to the MC Adapters and have all 4 with full swivel and quick disconnect if you want that option.
You mention REV 10 so it sounds like you want the loudest set up you can get. But we also have the ICON 8 surf speaker. It is the same size as the REV 8 and all fitment options apply to those as well.
I am not 100% sure on REV 10 and REV 8 fitment but you can shoot me an email at firstname.lastname@example.org
and we can take a look at measurements and see what would work for you.