I just made a stand alone system to run my servers and nothing else. My well is basically the same setup but with a 40 amp 240 volt inverter, 8 batteries and 8 panels and will run my well FOREVER, I have no electricity to my well because it would cost about $100K to run power up my mountain to the well. I could set it up easily to start a generator when the power goes out if I wanted to, but I don’t think it will be necessary. So far it has been working great for about 6 months now.
Does your inverter have the "smart load" feature? If so, you can make the rest of the place be powered from the smart load panel (i.e. if battery SOC is 50% or higher) with your server power coming from the main panel (powered as long as there's any charge left in the solar batteries). That way, instead of buying and maintaining APS for the servers, you add a cheaper lithium battery to your battery stack knowing that it won't be used to power the entire building, just the few on the main panel (assuming all other circuits are moved to the smart load panel).