if its just to connect to your stereo system then any basic stereo soundcard should do as all you need is left and right channels
having said that the more you spend on a card the better quality the sound is supposed to be
plus are you planning on watching dvds etc on the same pc
then you might want a 5.1 card these are cheap now
soundblaster live 5.1 only £27 (uk) direct from soundblasters website.
No way dude, Get yourself a SB Audigy platinum.......it'll have RCA, as well as midi, it will be able to hook everything up at once, including your one's and two's......this is my set up and I can record like a friggin' studio!