I got these at http://www.earmarkcaraudio.com/Xcart/home.php?cat=262
They are a little expensive but worth it. I have gotten several great comments on my lights. Great winter project for you. My cabin speakers are the Polk as well. They have the rings and LED in a set or you can just buy the ring and put in your own LEDS.
Tazz
Tazz 07' Moomba LSV --Kicker Marine Amps (MX700.5 & MX350.4) 6 polk DB651 speakers, 4 MB Quartz Marine Speakers, 10" Boston Acoustic Sub, Z-5 Cargo Rack, Custom Speaker/Light Bar, modified ballast system, Custom LED Rings
Live life to the extreme and no less!!