This is my 'Desktop' setup. It is Dell precision T5400 tower workstation with 16 GB ram and supports upto 6 monitors...6 years old though (runs on windows 2007)
I have a backup laptop (6 years old sony vaio - 4gb RAM) running on Windows 2007..it is constantly connected to a USB dongle.
Desktop is connected to Airtel Fibernet and also have Airtel 4G (always on during market hours as backup)..as soon as Airtel fibernet disconnects, i connect my desktop to 4G manually through ethernet.
All devices including monitors are backed by APC Pro 1500 and i get 21 minutes of backup if everything is on..my place also 5 KV backup so no worries there.
All 3 are samsung 20 inch monitors and the system is connected to Bose speakers as i love to hear alarm at specific points..