There are these pre-made bags that can fit over the 703 and then can, I believe, hang from the wall. I cannot remember the name of this. At least one of the manufacturers of these bags seems to get in giant pissing matches with Ethan Winer, who makes RealTraps.
There's also a Primacoustics room kit that seems fairly cheap, although I don't know how good it is...but Primacoustics makes the amazing Recoil Stabilizer pad, which absolutely fookin' rules, so their room kit might be good as well.
Another thing you can do is, rather than treat the room, you could consider getting one of those sE Vocal Booths or whatever they're called. They're not cheap, but you can take a lot of the unwanted reflections out of the room by using this with a microphone. You can get the project model for about $200, and the nicer version for about $300.
Ken
www.blueberrybuddha.com - studio
www.kenleephotography.com - photography