I've found the Solid Black to have the highest R-value, which we need under our soon-to-be-white oak flooring...the floors get cold here. We're also going to put in insulation batts between the joists, but even with that, it's not enough to keep my feet warm int he winter. Subfloor heating won't be happening because it's just a part of the rest of the house that already has white oak down--we're taking up carpet slowly as we get the $$ and replacing it. So we won't have heating under any of it.

ANYWAY, I can't figure out how a homeowner can buy this stuff. Does anyone know? OR is there an equally high R-value underlayment that is more readily available? TIA.