I'm also going to go the Stenner route.
I originally was looking at the fixed output pump on a timer. I'm still figuring out my automation needs though, I might have a new thread on automation later. I figured for independent operation I'd look at the pumps with built-in timers, mainly the ECON and the BDF series pumps. From my readings, I think the BDF pump will suit my needs more than the ECON. I'd rather have more small dosings per day/week than be limited to the 24 dosings a week max limit with the ECON series.
I figure the BDF 24-hour programmable pump will be fine versus the 7-day programmable pump.
As has been mentioned, the ECON pumps are indeed listed as "indoor only" pumps. Same with the BDF series. I talked to Stenner tech, they said there are no environmental limits (temp, humidity, etc) on the pump...their concern is rain. And as long as the pump is completely protected from rain, all should be well.
So right now I'm leaning towards a BDF 24-hour programmable pump installed in a small housing. Haven't pulled the trigger yet though. Even thought the Stenner will likely be a stand-alone installation, I still want to figure out my automation as a whole before I buy.