Use your ears to determine what sounds best! One thing to keep in mind is reflections off the rear wall, at that close proximity, can break down a stereo sound stage, or potentially make the sound overly bright with surround sound.
For absorption, I use GIK Acoustics Art Panel's (among others) and the dye sublimation printing is outstanding. High Rez photo or stock image printed on an acoustic absorber would make for functional art. The Golden Gate Bridge made for easy WAF for me.