As you said "I primarily use the system to listen to music. I do use it to watch TV but it’s not often." this is exactly how I use mine too.
I am using a JL Audio E110 (Not anywhere close to the level of subs you are planning to buy) but have never been disappointed by its speed and bass authority.
With your room size I feel something like a Rythmik E15HP2 as suggested by
@DB1989 or
JL Audio Fathom F112v2 or a
F113v2 (Same high level inputs as REL) would be a better solution. They will pressurise your room more effortlessly.
RELs of course are unbeatable RELs but more focused on tonality than the slam which you will never miss with JL/Rythmik.