My 75 build

[mark]

Drill the tank for the overflow and return and look into Herbies, they are truly silent.

I like CL rather than PHs in the display but you're talking another pump and depending on size, noise could be an issue. Lots of pictures of CL layouts on OM site though. Having all flow based on a single return a little more complicated to get random (look into Calfo manifold to help) and also more water going through your sump.

2X400W wow that's a lot of light (and heat and power), how deep you running?