The 9600SE is a "stripped edition" of the standard 9600 or 9600 Pro. Try to find a standard 9600 or a 9600 Pro.
The A7N8X-X has onboard LAN and sound. The sound is a simple Realtek based solution (the same as on the A7N8X (standard)). The A7N8X-Deluxe has the Soundstorm audio and a lot of other things as well. It is, however, about $50 more than the A7N8X-X. The onboard sound on the -X (and standard) sounds fine and isn't too bad as far as onboard sound goes.
Drop the network card, as I said above, the MB has onboard networking.
That case is fine for that system. It is very easy to work on and well built. Just put the extra casefan in the back below the powersupply and all will be fine.
