I have wired in Super bright white LED in my Heng long tanks, and the effect seems as good as the Tamiya flash without all the sounds of a capacitor charging going on. There is a little more focus with the LED then the flash unit though, so there is a small compromise. i.e less visibilty of the flash when viewing from 90 degrees.

So in my opinion, yes a cheap alternative is available. I have no idea about the voltage the DMD puts out to the flash unit though. THe Tamiya flash unit has that black junction box looking thing that goes in the turret. I am not sure what that is all about .

I suppose you could put in enough resistance in the Tamiya circuit to protect the Super bright LED????