There are so many cheap diy options now where you just install all the wireless sensors yourself. I think Simplisafe is the more poular one.
I would definitely install outdoor motion cameras. I have Ring floodlight cameras and love them. I used mine just recently when my camera went off late at night when I was away and some kids were acting suspicious looking into my cars. You can activate at 130db siren on it. Scares them away real quick.