Your gonna need more A/C.
Quest 105 Dual Dehumidifer is the best on the market. Most efficient by far. Heavy as fuck, but worth it. I'd get two for that size room.
Ionic works great, have used it for a while now. Most ph stable nutrients I have ever used. So I'm just not getting what your saying about what they are doing wrong.
I first noticed it when I had all the doors open to to all 4 flower rooms at once. The spectrum was different coming from each room. All the same bulbs. Only difference was age.
I doubt they will b quieter to be honest, but they will do a better job. I doubt they would be that much louder.
Adding another 6" fan, for an intake, reduced down shouldn't add any more volume.
Add another fan to your setup. One for exhaust and one for intake.
Personally I'd try to find larger fans. Your jus not moving enough air through the tent fast enough to get rid of the heat.
Large central A/c units would cool a grow of this size. 10 5 ton a/c's would work just fine.
3 or 4 400 amp 3 phase power supply. Any electric company would be happy to help with, you'll b a great customer.
Operations of this size pop up everyday.