Bombshell Minis make a few in their Counterblast pulp SF range. Look their online shop ("Counterblast" then "Lancers" or "GDF"). A couple in modern-looking clothes, a couple in space suits. I have them and they're really nice figures. Tails and proper digitigrade feet
Regiment Games used to make several packs, but closed shop a year ago - they may yet resurface under another name.
Mega Minis had some but they have also been selling off their ranges. Maybe contact them?
Denizen Miniatures (whoah, a blast from the past) have a couple of "catgirls" in their SF range, but these are more accurately described as "women in bathing costumes with big 80s hair"...
Couple of fantasy catmen ranges - Alkemy's Khaliman and Crocodile Games have the followers of Bast in their Wargods of Aegyptus game. Probably a big job to convert them though... unless you encounter them on a low-tech planet. I know, I know...
Does it have to be 28mm to match with existing figures? Khurasan makes a brilliant range of Felid troops in 15mm...