can't stress this enough, do not DO NOT use an internal sound card, they are great for outputting sound, but when it comes to input they are static. I've used a Creative Audigy Pro in a pretty well set up computer, still the same problem. External sound cards and guitar products like the TonePort are designed from the ground up to 1) not have any components in them taht cause static like fans or unshielded components, and 2) to be sensitive enough to get a good range of tone through them.

You can go 2 routes, one is to plug your guitar through an existing amp/modeller and then into the computer (using the headphones/line out in the amp/modeller) or plugging your guitar straight into the device through a mic input and using a software modeller (which can be more flexible and changeable but less authentic).

I'd recommend getting a toneport instead of a fancy sound card.

Worst experience i've had with a sound card was a professional one in a PC that i was using to record a voice over for a documentary (not my voice :)) and it was a top of the line cable and a sure SM58 and a top sound card, and still - totally bad quality. ended up using the camera to record the voiceover!