Im thinking P60 host / pill .. My issue , is they are just severely under driven , why build a SST 50 if your going to drive it at 2A .....
I just might need to hold till the XM arrives , as the SST needs at least 5A or 10Watts to come alive [ battery set up ] , and Im not sure a single 18650 can do more than 4A [ Ive gotten 3.7?A from the Samsung 30A ]
The XM-L are going to be ones to wait for since they can use quad die drivers, and we all know the random crap driver game with the cheap chinese sources. Generally, you'd be lucky to get a p7/mce with >2A.
Xtar, though, has shown to be a cut above. Hope your SST50 works out above 3A.
Unless you're doing your own pcb, it seems ganged 7135 are going to be the easy DIY solution, along with either an AMR or few cheapo lithiums in parallel. Maybe someone can find another regulator that works well in parallel and a driver with it mounted that's solderable.