Or you could do something like GIK alpha panels which are absorption panels with wood slats in front of it that does the diffusion part. Make regular panels and get some 1/8 inch wood with vertical slats and glue to front of panel. But I recommend talking to GIK to see what they say about their advice on what you should do. Its free service and you don't have to actually purchase anything.
Main theater: Sony 45es, 120 inch ST screen, Panny BDT500, Rotel RMB-1075, Rotel RSP-1068, Klipsch RP-280F, RP-450C, RP-160M, SVS PB13-Ultra x 2
Loft theater: Panasonic 60" plasma, Integra DTR-30.3, Axiom Audio M60, VP150, QS8, EP500