With that much space in your sump/fuge...I would just put the skimmer in the sump and keep things safer/simpler.
Your diagram doesn't show unions, but make sure that you are able to shut off/disconnect/reconnect every pump from the system for cleaning. (I'm sure you've already thought of that)
If you are making that into a 'fuge, then you might consider making the baffles out of black acrylic to somehow preventing light from going where you don't want algae growing.
40 Gal Hex, 10 Gal Sump, CPR overflow with Mag 7 return, Maxxima 35 RO
, 10K MH
pendant, 2 x 15W actinic, 1 yellow tail damsel, 1 high fin goby, 40lbs LR
.com rock, 1 red head goby, 1 algae blenny, Leather, blastomussa, sun, and hammer corals, green polyps, carpet anemone, 2 sexy shrimp...and more LR
critters than you could imagine in your worst nightmares.... Mantis in 5 gal