Camden,
Just to be clear I'm not trying to dissuade you from a sump. They do have some real advantages but they won't cure an unbalanced tank. Besides Paul B.'s thread, by any chance have you been checking out Randy Holmes-Farley's thread?
https://www.reef2reef.com/threads/randys-tank-and-learn-thread.1103636/
Randy is going step by step through his build and why he is making the decisions he is. Your tank goals are probably not the same as his but I think he does a nice job of compartmentalizing his decisions. He has a sump on his 120. If I remember right it is 4 44-gallon brute cans, each one with a specific purpose.
I like sumps and they have the advantage that, done right, you can set up specific 'zones' that don't necessarily play nicely together or that cannot coexist in the confines of a small tank.
If I remember right Matt (
@Fish Styx) has a cryptic zone in his sump. You need a very large tank to pull that off in a display.
https://www.reef2reef.com/threads/the-house-of-orange.965979/
What I don't like about sumps is that they encourage equipment creep and are often filled with nearly useless equipment that is only masking the issues in the tank.