If not simple flip flop circuits are easy to knock up which would give two different flashes and only use 6 cheap components
I might somewhere but its years since I built one, from memory they used simple ac128 transistors a couple of capacitors and resistors.I'm being lazy now but do you have a circuit diagram and component list to hand?
If I build one it needs to be from components easily available from such places like maplin to save me waiting for delivery.