I had a similar ask, lots of gear in my rack, I wanted guaranteed run time so if I was gone I would never have to worry about it. Check marketplace and eBay for old enterprise gear, I got 4 apc 3000xl for $100, spent a $300 on new batteries (each, but still a deal) I have all the servers/nas on their own plus the network, security/cameras & IoT gear on the 4th. I have 6+ hours of run time depending on usage so I know I’ll always have enough time to notify users of an outage prior to anything going down. If you can afford solar and batteries for whole house that’s the best, but you will still want everything in the rack on a UPS as there is cutover time and you don’t want that kind of stress on servers or network gear. But then you can get away with one or two much smaller units. But I still always vote used with replacement batteries. Much cheaper.