Hey guyz !

I have an account with Sirius radio and listen on line frequently .Only have 1 radio station up here in the bush where I live so $200 bucks a year is justified . I am running a patch cord from the headphone jack of the PC over to the receiver . Is there any way I can make it sound better than what I am receiving ? I know the signal is digital but by the time the sound gets to the receiver its a little cloudy and thats with quality cables .Should I be using toslink as the output from the PC to the reciver ?
Is there any internet players that have better sound quality than Sirius ?
I have never tried Pandora but have heard its good
Any suggestions or assistance would be appreciated
What do you guys use ?
M60,s Vp160 , QS8,M3,s Svs 12 . Yammy 3063 ,Panamax 5100,PS3,Optima HD80 Axiom Air