I'll keep recommending my fave for tanks in our range;
Eheim 1262
For your 180 you'd only need approx 1000 gph through the sump to satisfy your skimmer
I put my pump on a pad cut from
this stuff.
Everyone who's ever heard my sump can tell you it's dead silent
Pump's been running for 3 years this coming May with not 1 issue, and only 1 or 2 cleanings
Only drawback I'll admit to is the 80w rated power usage