Battery was a phone auto correct typo. Was meant to say heater.
For the pump system, do you need one pump for water and one for the air/blower?
I have found a decent spa pack with top side control, plus ability to wire up a pump and a low voltage light.
Understand your concern, admittedly I am new to spas but learning a lot online. I've done pool filtration before on my own above ground pools so don't figure it's too difficult to learn. Am determined to do it myself so that's where I'm heading...