I second the Audiophile 2496 (second link above). Great card, good sound, and now the can be had for around $100. You won't find anything too much cheaper with the same quality, and it should work great with Cubase.
I've been looking a lot at the EMU cards lately... http://www.emu.com
they hav al sorts of in- and outputs (even ADAT lightpipe...)
Creative has bought the company and is selling them in the 'creative professional line'