Ok, I'll go ahead and post my link:
http://macetech.com/store/index.php?mai ... ducts_id=1
That's the LED module, further down on the page you can see some examples of things people have done with these. We have cables from a couple inches up to 19", you just daisy chain the modules together with the cables. The only problem I can imagine would be the distance between the two circles. If you need to position any two LED modules more than a couple feet apart, I can't guarantee reliable operation. However we have had customers report 5 foot spacing with no problem in their application. If you did have problems running everything as one chain, the solution would be a second controller.
And this is the adapter shield that can respond to audio input:
http://macetech.com/store/index.php?mai ... ucts_id=11
Since I've linked products outside of Sparkfun's store, I'll atone for my sins by suggesting a few Sparkfun components that would help a lot.
Just to let you know what else is out there, Sparkfun sells an RGB module that you could use to do pretty much the same thing (it uses the same LED as the ShiftBrite):
http://www.sparkfun.com/commerce/produc ... ts_id=8579
With either solution you will need an Arduino, it's what the ShiftBrite Shield or Shifty VU Shield plug into, and contains the code that controls the ShiftBrites. Sparkfun has a few good options, this is most likely the easiest to use:
http://www.sparkfun.com/commerce/produc ... cts_id=666
ShiftBrites don't want to run on 12 volts. They might survive, but overheating will be a possible problem (especially on the playa!), and you'll be wasting about 75% of your battery power as heat. However, a 12 volt battery is the easiest to find and charge, right? What we need is an efficient way to step down the 12V battery voltage to something the ShiftBrites can handle. Luckily, Sparkfun has just the thing:
http://www.sparkfun.com/commerce/produc ... ts_id=9370
Connect the Sparkfun DC-DC converter to your battery, and set the output voltage to the maximum 5.5V. ShiftBrites will be happy, and you'll probably get days of operation from a single charge.
So now I've thrown like six different components out there to build this LED system. If you're not an old hand at this, you might be confused about the next step and whether you have all the components for the complete system. Don't worry, I've helped lots of people past this stage. If you can provide a sketch of your desired setup, with information like distance between LED modules and desired location of things like batteries, control boxes, and buttons and knobs to change patterns, I can draw up a wiring diagram and parts list for you. I can also help with the Arduino code to get the visual effects you want. Mechanical problems like mounting the modules and protecting cables will have to be done by you onsite, but that's probably enough to worry about in addition to the electronics.