The fourth PDF download choice (bottom right) catalog breaks out the US kits at the end, though most of them are reissues, most are already out I think.

I believe more then one company can have Star Trek and Star Wars kits.

Bandai, Revell, Zvezda and MPC all do Star Wars and I see those plastic kits available here in the US all the time.

That's not counting the endless toys, figures, metal and paper models and such from just about every model company.