Which reliable UPS to choose for an unstable network?

Question

Uninterruptable power source

Greetings! There is a task to purchase a UPS to power two workstations, a raid, monitors - for about 1600W. That is, the task is to protect expensive equipment. The network is extremely unstable. Therefore, the choice fell on the so-called. on-line UPS - with double conversion.
The first question is how to determine for sure if double conversion is required or if an interactive UPS is sufficient?
The second point is the manufacturer. I have very little experience: I used Ippon Smart Winner 1500 and Powerman BS1500. At various forums, experienced system administrators, comparing ippon with APC, clearly focus on APC, which "live forever in any conditions, and ippon fly in 1-1.5 years." Based on these considerations, I chose APC Smart-UPS RC 2000 VA (SRC2KI). The only thing that worries is the price. Should other options be considered, and if so, which ones? Or scrape the bottom of the barrel for a guaranteed APC? Yes, and is it really much more reliable than cheaper brothers?)
Perhaps at least someone can comment on the domestic electrical industry (and it is half the price, after all).
Thanks in advance!

Answer 1

I put APC not 1 = the first year any more. 40 pieces have already been installed.
They show themselves very well, including in "debilitating" networks (such as old houses in the center of St. (burned out. But the equipment remained intact.
Ippon bought 3 times at the request of customers. 1 burned out when turned on ...
My opinion - take a regular APC for 2000. Or 2 for 1000