APC is making large rack mount Lithium Ion ones now but they are crazy expensive.
I use an APC true sine wave one at home that runs a lot of devices and gives me 4+ hours as long as I don’t wake my desktop out of sleep. With the CSB “Long Life” SLA batteries and a slight modification to allow me to adjust the float voltage to the midpoint of what the batteries want, I can get 7 or 8 years out of them before they start losing noticeable runtime.
I’m waiting for one of these portable power station brands to move into the UPS market. The UPS mode they have falls a bit short of true UPSes currently.
The one I’m using is over 20 years old. I have a much newer smaller capacity one with lots of bells and whistles like digital display and remote management, but it needs new batteries. The charging circuitry is much more efficient also, my current one wastes around 20 watts just keeping the transformer/rectifier online. When my current batteries run out, I’ll probably move to that one, the power here is very clean and reliable so I don’t really need the huge runtime (nor am I running anything critical out of my house anymore, and my cellular hotspot and laptop battery can take care of any outages longer than a couple hours).
I have this one sitting around that is simulated sine wave with a huge external battery pack. Needs all new batteries but that sucker would probably run me 12+ hours. But there is no need for it, nor do I want to run a stepped wave to my equipment.
At one time I considered building a battery box and hooking up a couple deep cycle Optima batteries, but that was when I had servers and stuff running here.
For just running a camera or two, the cheapest simulated sine wave ones should work fine and give several hours of runtime, the wall warts should handle the fake sine wave fine and even if one burns out, grab another out of the drawer.