Re: SST-50 EDC Light *Feeler*
http://www.shiningbeam.com/servlet/the-132/3-dsh-Mode-Regulated-Circuit-Board/Detail
What about this driver? Basically your 2-mode plus an ultrahigh "Boost"-mode. Considering your heatsinkinking 2.5A for short periods should be ok.
Do you also consider a MCE...