Well if you really want to avoid the hold switch, you can solder the lights to the wifi switch. This seems like the good way to go since you don't really ever need to turn the wifi off anyway. If you wire them to the wifi switch, then when the switch is in the down position, the lights will be on. You'll have to ask someone else for the diagram but here's what I know:
You can get +5 volts from the motherboard. You would want to use this if your using a lot of LEDs.
The wifi switch provides a ground.
You can get +3.6 volts from the powerboard. This is probably more suitable for what your doing.
You can get a ground from the motherboard.
You can get a ground from the powerboard.
To use the wifi switch as the switch, you need to connect the - of the LEDs to the ground of the wifi switch, and the + of the LEDs to one of the + points I mentioned above. I would suggest toe one on the powerboard. That way you won't need a resistor for white or blue LEDs.
Of course if you want the LEDs to be sound-reactive, none of the above applies unless you use an amp.
To make them sound reactive, solder the - of the LEDs to the - of one of the speakers. Solder the + of the LEDs to the + of the speakers. This way is easiest but requires you to add your own switch. I have no idea where to get one small enough.
The method for sound reactive LEDs using an amp is much more complicated so I won't get into it now. If your interested I'd be glad to help. Otl have to sati till tomorrow. It's like 11:30 now and I'm hecka tired. I hole the above info helped.
