Hi, You use room treatment to solve certain issues that will not be altered by your equipment selection. Can you describe your actual issues? Are you having problems with imaging, low frequency buildup, etc? It is hard to know what to recommend without knowing what you are trying to improve. The first thing I notice is that your room is exactly twice as long as it is wide. That is going to give you some really nasty standing waves at certain lower frequencies and their harmonics. I would expect that to not sound so good. I just googled to find a reference for you and found this link:
http://artsites.ucsc.edu/ems/music/tech_background/TE-02/modes/Modes.html
The fundamental frequency of concern is going to be more effected by room geometry than surface treatments. Can you angle any of the walls? This can be done in small pieces, perhaps four feet long so that you do not lose too much floorspace.
Another typical problem in a room is the first order reflections. These are much easier to reduce, but using absorptive treatment won't do much below 100 Hz.
An easy way for you to find those is to use a mirror. Sit in your normal listening position. Have someone move the mirror around flush to the side walls and the ceiling. If you see the tweeter in the mirror, then that is an area of a first reflection. Those points will all be somewhere between the speakers and you on the side walls and ceiling. This happens on the floor as well, so just put a rug in between you and the speakers, you can use the mirror to see where the rug wants to go as well. The material that you use for the absorption matters as well.
There is a lot more to this than what I am pointing out here, but these are the items that typically cause issues in a rectangular listening room. I would need a lot more info to actually suggest more. Hope that helps.
