I habe the same setup you do, 75g 20L sump. I am going with a 150SSS. I had a 110NW on a 40B 20L sump and i personally felt it was a good size for that system but feel its too small for over 65g. Not saying it would not be fine cause it will so if you have it already use it. I just like a little larger skimmer. Also the SSS are a different skimmer and perform differently, I was shocked how large the 150SSS was when I go it.