LED dog collars can be great for increasing the visibility of your pet - but I recommend using them in combination with something that's reflective (such as a harness or leash). Bright headlights can often overpower LEDs, which means they aren't as visible for people in cars.
Choosing an LED or lighted collar is the same as any dog collar - at least in most respects. It needs to be comfortable for your dog, durable, strong and easy to take on and off. With that said, there are some extra considerations: