I know this won't work for most Vader guys, because it's not going to be 100% accurate, but it's a great budget solution.
This is from a $4 kit I bought at Frys. It only controls 2 LEDs but at $4 a pop I guess you could buy 3 and set each one to a different blink rate.
The 2 LEDs are not adjustable themselves, you adjust how quick each LED blinks in relation to the other. The adjustment is a dial so it is adjustable along the dial. I guess if you knew about electronics you could build the kit with different dials and get a different blink rate.
I don't know how to embed a youtube video so click here to watch.
The kit is the Velleman MK102.