Aussie Installer

I use HDMI over IP converters that utilize UDP. You need to get converters, not extenders that only do 30m and cannot be used in a data switch. I use Cat6 cabling and Gigabit switches. The limits are 90m distance and the amount of ports in your switch is the amount of monitors you can connect. 24 port switch is 1 input, 23 monitor outputs, 8 port switch is 1 input and 7 outputs. An uncompressed full HD HDMI signal (1080P inc audio) is up to a bandwidth of 1.6G/s, so there is a little degradation in quality, but most people would not notice it. I use these also for AV distribution in clubs with no issues.

In the set up of your CCTV there should be access to blank out areas of the cameras viewing angle, usually called privacy and even in cheaper kits there are usually 4 privacy curtains per camera. You can angle your camera up and then black out your neighbors. Alternatively, you can talk to your neighbors who may actually like the idea of some added security and want you to include more of their outside area.

2 x 24VDC 250W solar panels connected in parallel. Generic brands work well, but I look for panels with a decent warranty. 20 Amp controller. Preferably waterproof. 2 x 12V 150Ah batteries connected in series. I use Ritar regularly. IP68 rated electrical enclosure to mount the electronics. From local electrical supplier. A lot of routers, access points, switches, PoE IP cams etc are 12VDC, so find the right ones and there is no need for an inverter, or transformers. You can then use wifi for close cameras (Access points really should be mounted externally as the signal bounces off metal) and wireless bridges for long distances between cameras, but they will need their own solar power. I use Ruckus. Be careful of high speed PTZ PoE IP cam's as they use ACV, not DC with a large current draw to spin the drive motors. As an added bonus, you could use an inverter to get your local AC mains Voltage on sunny days. I don't know the currency conversion between you and AU, but you might want to put an extra zero on the end of your budget figure.