Jay, have you tried floppydisk.com? Their site only shows 3.5 and 5.25"
floppies, but they do have 8" too (although not cheap).
Not sure if they'll have the hard-sectored ones but they have SSSD
soft-sectored (for my RX01) at $90 for a pack of ten. Going rate on ebay is
$25-35 a pack...