Here's the wall defense I'm using. It's set up so I can paste whatever defense structures I desire on top of each other. I can use any combination of: laser turrets, regular turrets, flamethrowers, and artillery. Each defensive component has it's own blueprint. There's a straight blueprint and a corner blueprint that can be overlayed.
Each blueprint comes with buffer chests requesting everything needed to repair/replace items on the wall using the bot network.
Turrets, comes with full line of clockwise-facing yellow belts and yellow inserters (for placing early game)
Flamethrowers, pipes in place and ready to be connected to the corners
Artillery, Includes radars and requester chests for artillery shells
I'm a new player so any suggestions for recommendations are very welcome!