If you're looking for a 1TB drive then your options are limited to only one or two models that I'm aware of. Pretty much any SATA drive will work fine, although I'm not sure if there's any limitation to using SATA I vs. SATA II. IIRC, the S3 Tivo has the jumper installed to limit the transfer rate to SATA I. I don't believe the Seagate or Maxtor SATA II drives have this jumper included.