I have no idea of the models, but most of the lights for life jackets I've seen in my life are like those in the link provided by climberslacker. They have been simple little lights, with a battery and a flashlight battery. I've also had a strobe.

Both would always be better than none. If you have one, I think you'd pick based on your conditions. The strobes are far brighter and far easier to see than the other ones I've seen used. I'd check out the times each was expected to last when choosing.

However, if you expect to be in an area with a good amount of traffic, take the strobe.