Stickman, re your floors, you have been very spoilt by having concrete floors in your current room.
Any suspended floor you have now will need the speaker isolated (de-coupled) from it, not spiked or coupled in any way, otherwise the floor will become a sound board for the speakers.
There is one way for you to be able to spike (couple) your speakers in this room to get the very best out of them still. It radical , but then maybe you are as much as I am. Seeing you have a basement underneath this suspended floor, you can have two concrete post poured from the basement floor up to where your speakers are positioned, this way they'll still be on a concrete support.
Cheers George