There is an FAQ on the Current site that covers a couple of your questions. I'd link it if I wasn't on my phone here. The single and dual will work with the Plus as well as a number of other lights that meet the voltage requirements.
As far as the stress, I don't know for sure. I keep mine over shrimp, and they never seem to care about the sudden on of the light on a regular timer.
As far as the stress, I don't know for sure. I keep mine over shrimp, and they never seem to care about the sudden on of the light on a regular timer.