If the board has usb 2.0 then go with the audigy 2 nx. I just installed mine last night. It sounds incredible. I would say even better than a movie theatre. I'm running an mtx 8000 12" at about 400W RMS off a MTX 282 and the factory ford escape speakers on an 400W MTX 404. I sat in the car for about 2.5 hours last night listening to it.
The 2 MTX amps eventually heated up the interior to about 98 deg, I had the console out so I couldn't turn the AC on and had to stop.
You can use something like this to convert to RCA then run on hi quality audio cables:
He was out of thoes, but also had the same version in a cable form. That's what I ended up getting, and they were pretty good quality.
Again, the sound I got out of the overall system is fantastic. I have a Cambridge soundworks 5.1 system on an audigy 2 with Harman Kardon speakers & 100W 8" sub in the study. The audigy was pulling bass out of songs I have never heard on any other system. I would give it a 10 out of 10 on audio quality. I'll post pictures once I set up a website.