In a room that size definitely go with monitors and a sub as it’ll be much easier to manage the bass and you’ll get bass down to a true 20Hz that you won’t get with floorstanders.
I've been happy with the soun bar for years and I tend to not like loud sub noises anywyas
You’re in a whole different world with a good 3.1 setup versus a sound bar — not even close. If you’re equating subs with loud you haven’t heard a properly integrated subwoofer. Ideally you don’t hear a sub at all, but you can certainly feel it. What many people don’t know is that subs not only greatly improve bass but also have enormous effects on improving overall soundstage, imaging, and detail. IME the two most important speakers for maximum HT enjoyment/involvement are the center speaker and the sub(s). Get those right and you’re all but assured a great HT experience if they’re set up properly.
As for speakers the Emotivas look fine, but I’d recommend taking a look at SVS. They do nothing but speakers and offer a 45-day completely risk-free trial including shipping both ways, which is rare and really nice. And their speakers and subs get excellent reviews and offer great value as they sell direct. I’d recommend their Prime monitors and center speaker (which is outstanding BTW) and their SB1000 Pro sub that, very importantly, has its own integration software that will make it much easier to achieve excellent and well-balanced sound in your challenging room (square rooms are awful for sound, particularly with bass issues). Plus, their customer service is absolutely top notch, which is nice to have especially if you’re new at this as the devil is in the details in achieving the best possible sound out of your expensive equipment. Ok, that’s all I got. Hope this helps, and best of luck in building a great HT system.