This is what I know of the Dutch fire department. Use it at your own needs.

Their network has two parts. The network lines. Which unlike corporate network connections where you buy a network line with certain specs
( bandwidth, uptime, performance), specs that are dictated by the ISP and you just pick the options you like. They have reversed this process. They dictate the terms.
( bandwidth, uptime, performance). And where usually you as consumer can get a refund if the network lines are not up to specs, they have that reversed to. Meaning if the ISP does not deliver what they promised. They get sued.
This results in only a select group will even start considering suppling network lines. As 99,999% uptime and fall back are hard to deliver. Even more when you get sued for bankruptcy if you fail to do so.
(remember this is networking in layman's terms. Although the clue is the fire department dictates term and not vise versa where you get lines, and no refund if they don't work)Second part are the computers. A fire department in Roermond
(Netherlands) uses a NAS cluster on their primary location, and a full backup a couple of kilometers outside the city which can when needed fully replace the primary location. Again in layman's terms.

The use multiple servers clustered on the main location for all the data. That cluster is fully synchronized with a backup location
(housing all the backup servers for the city, so not only the FD). On the main location they can handle one server going down. And in emergency's they can change location without data loss or loss of functionality.
Now, both points are not for a voluntary fire department and are used in The Netherlands by the government. Point is, when you are setting up stuff that is used to save lives. Don't do
partial-solutions. You are setting up the tools needed by others. Without that they can't even start doing their jobs.
First make sure you know what you need, software wise, network lines and hardware. Simple questions like why do they need computers and what do they need to do. How important is that software and what happens when we can't access that software / data for what reason soever.
Write a simple
(and non technical) report for that. And take that to a company that knows what they are doing
(and have done it before). Set it up simple, efficient but most importantly make sure you get what you need (
no more), and no excuses.
If you have any doubts about the solution offer, ask until you understand what both sides want and can deliver. It happens only to often that people ask for
computer / software / ICT solutions without fully knowing themselves why they, and what they need. And that companies deliver services you don't need, never asked for and keep saying
well, that's just the way it works.