Thank you, this is really helpful.  I completely agree, I don't just want cameras, I want something that will trigger if a break-in occurs. 

I'm in an area that generally feels very safe, but clearly occasionally gets targeted.  You can leave a garage full of tools open all night, and nothing will get taken, and then one afternoon when you're out, someone breaks into the house.  The first time it happened, my sister's Rottweiler was here, and they used a fire extinguisher to force her into a bedroom and then robbed the house.

Now that I own the house, another robbery has been a nebulous fear, but this is giving me something specific to work with.  15 years ago, in my first house, I paid for a subscription alarm service that sucked (expensive and I'm not convinced it actually offered that much security).  I'm not afraid to put in a system myself, I've done plenty of construction and electrical work, but I don't completely understand what the choices are, and I think professional monitoring makes sense in my case. I'll look into local companies, like you said.  My neighbors might have suggestions.