What software to get the best sound out of my iMac G5?

I've just bought an good external soundcard (with a firewire connection), hoping to bring the sound quality on my iMac G5 closer to what I have on my stereo. I'm happy with the card, but it shows the limitations of iTunes. It's particularly striking when playing CDs, the sound hasn't got much life, the musical picture is lacking in definition and depth, compared to what I'm used to on the stereo. I suspect the problem comes largely from the amount of processing. I've tried other players : Audion sounds clearer, more transparent, but still a bit grey. The best sound comes out of the simplest software, probably because it just picks up the data from the drive and directs it to the soundcard with minimal interference. So far the best sounding software I have found is Simple Audio Cd player 101- good sound, but the features are really minimal...

My question : Does anyone know of other software that would have "audiophile" sound quality, and a few more features than Simple Audio Player? Fast Forward would be nice :-). Also ripping features to some lossless codec? I've been looking and looking...

Thanks for your help