Here in Nashville, I found the 703 panels at one place only, it was hard to find locally. $103 per case of 12, two inch panels 2'x4'.
You can order them online from
www.atsacoustics.comHavn't tried ATS so cant vouch for service.
The 703 is what many of the DIY studios here in Nashville are using. It's much better than foam and traps freqs all the way down to 100 hz if you double it up.
Placing it in the corners of the room will make the most dramatic impact immediately. You will all of sudden notice the bass really tighten up.
I like the stretched rayon idea, but I used soft burlap. Got it at fabric store for $2 yard. I made 15 panels for less than $300 and an entire weekend labor though.
I'll get some pics posted of my studio control room with the panels soon