You didn't state your price range.
M-Audio Delta 44, about £80-£100, PCI card goes inside your PC, all connection are via an external breakout box.
http://www.nusystems.co.uk/music/214...o+Delta+44.htm
If your thinking about spending a bit more, you could try the Edirol FA-66.
http://www.nusystems.co.uk/music/20179/Edirol+FA+66.htm
BTW, the Delta 44 and FA-66 is what alot of professional studios use.
These cards are also used where high SNR and spectral purity are important.