I finished the panels yesterday. Haven't got them hung yet but even just placing them at the first reflection points they seem to make quite a difference
Here is apic of one of them, I alreay had a bunch of stone wool (safe & sound)here so I just used that. When I do the bass traps for the corners, I'll buy some of the semi rigid FB from HD as was posted above and make them 4.5" thick. I ended up using brown gill cloth which matches my couch quite necely.

There is few more pics in my gallery if interested
Thanks for the help everyone
-jay