9 Months later, I return..... Sump Question

Well, nine months later I have returned. My 55g is plugging along, relatively mature at 11 months of age but over stocked and reached its limits in fish and SPS.

Sooooooo; I did what most do in this situation, bought a drilled 180g with a corner overflow, put it in the living room for the wife to stumble over last Tuesday night when she got home at 9pm from work!

Anyway, working on a 60g 48" long tank as a sump / refugium, and, I am looking for guidance as to the compartment sizes within the sump (downflow area with skimmer, refugium, and return area.)

Any thoughts ????