Personally, I'd recommend these. Incredible bang for your buck. http://www.parts-express.com/pe/showdetl.cfm?partnumber=300-...
You'll need an amp. http://www.parts-express.com/pe/showdetl.cfm?partnumber=300-...
To run from the headphone port you'd just use a simple male 3.5mm male to RCA(red/white) male.
I imagine the headphone port quality is terrible and the post mentions it. Apparently this is a cheap USB compatible option http://www.meritline.com/usb-sound-adapter-channel-volume-co...
This entire setup should run you well under $100 and sound great.