I installed an EV-100 on my 25ft Pursuit with a 250 Yammie 2 years ago, and could not be happier. I was on the fence about getting the bigger pump, but as the info above says I matched the ram capacity to the pump, and have had zero problems in 250-300 hrs with the .5 pump. Not sure if your E-tec needs to be running. As long as the AP is powered up it should control the E-tec with the kicker.
Good luck with your project.