As mentioned. AVS has a few threads on it. Although they’re about 5 miles long lol.
The TR thread, and the hideaway theater are good starts.
For just quick recommendations, crowson and Clark are good TR devices. Dayton has one that’s affordable, but some of the cheaper ones feel like on/off more than linear extensions of bass. I have a “hover couch”. Basically I mounted a subwoofer driver to a baffle in my couch and it sound sits on isobaric rubber isolators. The couch makes zero sound, and only acts as a TR(tactile response) device operating from about 22hz and lower. My subs are useful down to 14hz or so but my house is on a concrete slab. So a lot of the bass energy gets absorbed. I do not like my couch to shake unnaturally and that’s why I don’t run it up much past 20hz. Just want a nice extension. The subwoofer driver feels like a natural extension of the in room subs as opposed to some of the shakers that just feel weird. So yeah. I’d build a hover BOSS or some version of that. Cable will be tricky but there are many solutions for that.
Also. Being in the middle of the room is the worst place you can be for bass. You may want to experiment with the placement of the couch.