Scott -
US Recording Media still lists them on their site for sale.
However, you should be careful. Although Type II cassettes do sound better, CrO2 appear more likely to be unstable over the long haul. From the
International Association of Sound and Audiovisual Archives website:
"The magnetic layer usually consists of two parts [or components]: the magnetic pigment itself, that takes up and holds the information, and the binder that glues the magnetic particles together and onto the substrate. The following magnetic particles are in use: g-Fe2 03, used for all audio open reel tapes, and for IEC type I audio cassettes; CrO2, and chromium doped particles, as used for IEC type II audio cassettes and the earlier video cassettes, some of which are also used for digital audio recording, e.g. U-matic (PCM 1600/10/30), Betamax (PCM F1), VHS (ADAT). More recent magnetic pigments known as metal particle (MP) have a core of pure, metallic (non oxidised) iron with an inert ceramic or mineral layer to protect them from oxidisation. These are used in IEC type IV audio cassettes, R-DAT cassettes, and video cassettes used for digital audio formats, e.g. DTRS. The stability of g-Fe2 03 magnetic particles is not questioned, although CrO2 and chromium doped particles are less stable magnetically. Some MP tapes are threatened by oxidation, or corrosion of the particles. The MP coatings at greatest risk are those manufactured in the late 1980s and early 1990s prior to improvements in passivation techniques. A more recent development is the use of thin, vapour-deposited metal coatings known as metal-evaporative (ME). Some ME tapes suffered catastrophic failure as a result of the metal layer flaking away from the polymer base-film.
If you're doing non-fidelity critical stuff that you'll want for a while, consider sticking with Type I.
= Justin