Thanks, John. I did look into Sigma beforehand and unfortunately, they sell SWNT's that are significantly smaller than what I'm looking. Thanks for the papers, Andrei. I do realize what I'm asking for is very unlikely to be commercially available at this point in time, but I was hoping that there was some obscure company or group that would be providing these.
No on sells them for a simple reason - free-standing SWCNTs llarger than 6 nm in diameter cannot exist. They will collapse forming graphene ribbons. Read:
S.V. Rotkin, Y. Gogotsi, Analysis of non-planar graphitic structures: from arched edge planes of graphite crystals to nanotubes, Mater. Res. Innov. 5, 191-200 (2002)