Here's the problem I see.
There are already diy security systems available online or at Home Depot/Lowes. Most people who can set up a grow sizable enough to need a security system would most likely have the know-how to install the cameras. Even small grows need some handyman skill that can be applied.
Beyond that, there are already companies that offer home surveillance installation services but do so without advertising that it is for a grow. And by that I mean, would I rather have a service truck that said something generic like “Bob’s Security Systems, keeping you safe” or one like you would start which could read “Garden’s View Security, Giving you piece of mind on your peace plants”. It really makes no sense to put yourself out there as needing a security system for growing when you can get one by more discreet needs.
I would look into installing mini-splits or helping people run their duct work to vent threw their roof, imo. There's no real denying what that shit is for, so offering a discreet service for it that people can trust seems practical to me.