I personally wouldn't spend that kind of money for DC backup, you can easily do the same setup yourself for ~ $850 and save yourself 40%.
- $250 - Tycon TP-BC24-300/TP-BC48-300 (powered via AC - output 24/48v)
- $400 - (4) 12v 51aH AGMs (connected to TP-BC24-300 or TP-BC48-300)
- $35 - Blue Sea 5025 Fuse Block (connects load to TP-BC24-300 or TP-BC48-300)
- $150 - Yuco IP65 enclosure
The benefit of the fuse block is that you can easily connect your gear and you've got another layer of protection in case of power surges.
If your site is primarily powered by AC and you don't have a ton of outages you should also consider used batteries - do not got that route if you are using solar as your primary source. I've picked up 75aH AGM batteries for $40/ea. which is a massive savings when you're talking 20 batteries at a time.
There is a little caveat here though, I only buy batteries that were used by large commercial projects where they were on standby almost the entire time. Government or water dams are a good source as they replace their batteries every couple of years even though they are perfectly fine and may have never left the charger.