They are the same roof, but as stated above, the premium comes with a headliner. The headliner gives it a more finished look on the inside.
Yes, you can purchase the headliner separately, but IMO it's pricey, Polaris part# 5813912 apprx $180, and you will need to purchase the speed nuts and dart push pins for attachment.Can you buy the headliner later? I have sport roof and want the liner for noise and to keep moisture from collecting and falling on me on cool mornings. Also think is would be quieter. How is the dome light wired?