Recent experiences have suggested to me that Room Correction EQis not only far from panacea, it's not clear if it's worthwhile. Indeed, last year when I had corrected/boosted response at the listening position I had so much boom elsewhere it was causing lots of unnecessary rattling and made guests uncomfortable.
Meanwhile, I do like to do small EQ adjustments by measurement and ear, those actually do seem to help and don't do much harm.
So count me as a new believer in the need for room treatment, especially bass traps.
Leading bass trap manufacturers include Tube Traps (cylindrical and quite expensive for the larger ones), Real Traps (somewhat less expensive, look like better value), and others.
It will be a big problem figuring out where to put these things, the room is already quite stuffed.