In my spare time I still look at options for the computer.
Since the case that I am recommending does have both handles and 5.25" bays I was thinking about what would it take to actually add speakers to the system. of course part of that is also do they still make them? After all one of the side considerations for this system is to make the case portability friendly.
Well I found three. The perfect one that goes with the case is the Logisys FP308BK speakers. They have the same type of grill behind the speakers that the Master Case uses. The other two that I found had some nice features but had problems. One had an amplifier with volume control and you could swivel the speakers. The molding on the plastic looked great but the problem was that it only comes in white. White definitely would stand out and I am not sure how easy it would be to repaint it. The final one was black and also had a volume control and amplifier built in. The problem to me was that all of the pictures showed a very cheap looking case including what was visible when mounted in the computer.
All three has the same problem in that they came with a 3.5mm male to male cord to connect the speakers to the headphone at the back of the computer. Since the Master Case has a special expansion plate that you can run your mouse and keyboard cables through to provide strain relief, this plate would also allow this cord to pass from the inside of the case to the connector on the back panel.
I also looked at it and it would not be hard to make a cable to connect these to an AC'97 10 pin header and plugging it into the AC'97/HD-audio connector on the motherboard.
So this is a nice option. However the truth is that for a LAN party you will be using headphones most of the time.
For me, I had picked up a nice portable Jensen speaker set to use with my tablet to listen to Old Time Radio shows in the car while on trips. This sits nicely on the desk or the top of the computer case. It also has the advantage that if you connect only the USB cable to the computer it will be recognized as a USB sound card and works very nicely with the computer. So I will be continuing to use this with a new system.
If money is no object you can get some really nice 7.1 speaker systems or an optical sound-bar to connect to the computer.
I also found some nice 3mm and 5mm LEDs that came wired for 12v use. For $10 through Amazon you can get 10 LEDs and panel mounting grommets so that you can easily drill holes in the case to illuminate the ATX IO-Panel. Add some heat sink tubing and a MOLEX connector to provide power and you can have a very nice looking addition to the case.