I have an angle-valve IO-360-A1A.
I used the cooler Vans sells for the RV-10, and I made a mount similar to the RV-10 mount, but with different angles to match the angles of the RV-8 engine mount better for fit and clearances. I then made an aerodynamic adapter to the 4" SCAT tube.
If/When I do it again, I will mount the cooler perpendicular to the firewall as Carl F. shows in post #2 and make a different aerodynamic diffuser/adapter for it. There are several old threads here that show good ideas for the diffuser/adapter. I would also favor having the mount to the firewall provide a diagonal brace to the cooler mount flanges opposite the firewall, rather than Adel clamps to the engine mount - but that's just me.
I think that cooler is the bare minimum that you would want. Worth considering one of the better-cooling SW coolers.