If it helps, here is what I am curently using on my 120g (mixed reef). I perform water changes every 2 weeks and change up filter socks every 5 days.
-skimmer- Reef Octopus Diablo 160 XS (If your stand is similar to mine, you'll have just enough space to fit this skimmer.)
-sump- 40gal DIY 3 chambers
-overflow (perhaps a cpr internal retrofit - see brs)- PF-800
-return pump (low-ish flow)- Mag 9.5
-lights (led most likely) TT-AL15 (x2)
-display flow (mp10 on hand, but that's not enough) koralia 1150(x2)/WP25(x2)
-ca/alk/mg dosing (two extra brs dosers on hand) Kalk stirer
-ato (used ato.com single switch on hand...but prefer the double switch version on my 46)