The driver came with the light. It's 5 mode buck with that stupid next-mode memory. The next mode can be fixed by putting a smd resister (usually 330ohm works good) on the proper capacitor. I just haven't had the time to identify which capacitor powers memory. It would then always start on high after the light The driver uses PWM for the modes. Probably not a problem for my application, but I would rather low be true low and not high speed on/off pulses at full power.
It's probably a pretty cheap driver that can be acquired from the various Chinese vendors. If you would like, I look around.
I am hoping to eventually find a good budget non-pwm driver. If I do, I'll do my best to remember to let you know about it.