Try e-mailing The Insulator. He's a regular on this Forum. I'd wait a few days to see if he 'shows up'. Feel free to tell him Jay J on the Forum sent ya.
My best to ya and hope this helps.
PS: My $.02 says you'll end up using blown fiberglass insulation if the wall cavity can handle it. At some point, whoever or whatever contractor it is you call in, they'll tell you for sure. They may have to drill some pilot holes to check some 'things'. This would be normal.