The SoundBlaster cards for pc's have the ability to load 'soundfonts'....which are digital instrument samples. There are hundreds of them (free) on the web, or you can buy commercial samples. So, for that ability (if it applys to the card you are looking at)...I like the SoundBlaster. I don't know what the other card is like, so I cann't help you with that one.
Other options for you, though, might be to look at 'soft synth' sounds...that will work with the card you already have in your laptop. This type of sound usually has a bit of delay to it when played 'live'...but is great for playing things that you have already recorded.
And the cheapest way to go would be to get midi cables, and use your Casio as the sound device...playing the midi on the computer, and routing the midi data, thru the midi cables, to youe keyboard. You can also record the Casio as 'audio' using the line in or 'mic' input to the laptop, from your Casio's headphone or line out plug.
Here is a free audio recorder program: http://audacity.sourceforge.net/
And here is a really nice midi/audio sequencer program..at a great price: http://www.pgmusic.com/powertracks.htm