Hey Frack!
Your just the guy I need to collaborate with. I have had many of the same ideas and I am slowly learning the code for arduino, raspberry pi etc.
I plan on using multiple arduino and raspberry modules and touch screens in order to monitor, take actions and report via lan and GSM.
2 eBay sellers come to mind for items I have purchased from there is seller:kingelectronics15 and seller:gc_supermarket. Aliexpress is and extension for Alibaba.com where I buy my solar panels and batteries for my future Philippines retirement business (if all goes well

). You actually can sign up at Alibaba.com as a business and with business attitude order some very reasonable solar equipment.
here's are some items I purchased: MINI V4 Wireless Data Transmission Module + Calling GSM GPRS SIM900A M105
( 351493870847 ).
Ethernet Shield W5100 for Arduino Main Board 2009 UNO ATMega 328 1280 MEGA2560
( 201192051472 )
UNO R3 ATmega328P ATmega16U2 2014 Version Board & Free USB Cable for Arduino
( 381104046739 )
1PCS LM75A Temperature Sensor High-speed I2C Interface Development Board Module (serial for arduino scl sdl)
( 221948627765 )
Quantity: 16
Voltage Transformer Active Single Phase Voltage Sensor Module for Arduino Mega
( 371113461110 )
100A AC Digital LED Power Panel Meter Monitor Power Energy Voltmeter Ammeter
( 131569692590 )
Mega 2560 ATMEGA2560-16AU Board (Arduino-compatible) + USB Cable Funduino
( 301723529878 )
I use the arduino mega to learn from as I believe the plentiful i/o available allows for more functions from one board. Also there is more memory so your lcd's won't matter on memory. The raspberry Pi 3 is a bit pricey but has an sd card expansion slot but I can research an inexpensive card for you if you like.
I will be very interested in seeing how your journey progresses. Now I just have to wrap my mottled brain around coding.
regards,
SN