You'll want a tail light, too. I've seen enough people driving without their headlights on at night that a reflector alone doesn't cut it.
I currently use this light combo
https://smile.amazon.com/gp/product/B01IO12ZPO/ For my ebike, I used this headlight with a different lens
https://smile.amazon.com/gp/product/B006QQX3C4/ It's bright, but I wouldn't charge the battery on anything flammable. Both are bright enough for doing 30+MPH at night.