If I were you i would go with the Skmiz Monster 163 DC Series for your 120.. They are so quiet you can even tell they are running.. The water that trickles down your Overflow boxes is louder then the pump running full blast. The skimmer has a killer controller, feeding mode and a couple of other options. Also, if something breaks on the skimmer, pump, or any part on it etc etc you don't have to deal with the MFG in TAIWAN you deal directly with Bulk Reef Supply which no other SKIMMER in the world does that FYI.. Example something was not working currently with my pump and BRS had a brand new Skimz at my front door in 2 days.. I have been in this industry for over 25 years and have owned quite a few skimmers in my time. I have owned a Reef Octopus, Vortex, Deltec, Bubble Magnus and the Skimz blows them all away. Not to mentioned they are priced very reasonable. I have a 120 and my Skimz Monster DC 163 Series are rated for tanks up to 250 gallons. They make a couple of different series but for my tank and specs the Monzter 163 DC was the best fit for my tank.. i ADDED A LINK FOR YOU TO CHECK OUT THE DIFFERENT KINDS THEY MAKE..
http://www.bulkreefsupply.com/prote...protein-skimmers/internal-skimz-skimmers.html
120 Mixed Reef
Ecotech M1 pump
Skimz 163 DC Montzer Series skimmer
Custom sump / Refuge
2 Maxspect Gyre XF130's Pumps
2 AI Hydra TwentySix HD LED Fixtures
Celestial C35W Maxspect Grow Spot light
Aqua UV Ultraviolet Sterilizer 25w
BRS Dual Media reactor
Eshoops IV Master doser
Smart Micro Auto Top Off