small sun zy-t13 or zy-t08 depending on what format you would like
ps: i got the light today, great work!
edit: the zy-t13 is the only light i know of thats confirmed to fit the crelant head. the zy-t08 will not. the t13 is basically a clone of the 7g5 v2 i would think. head and battery tubes are interchangeable, if you think you would want single cell, or short 2x16340/18350