I am looking into rack mount UPSes. I have 8 servers to take into account, each a Dell. There are so many to choose from and financially speaking, it seems best to buy a few 2U rackmount UPSes that will each service 2 servers. The ones that look good are 2200VA and above. However, I'm still not sure if that is good enough for my needs. Our computers don't have any more than 550W internal power supplies, so I'm guessing the server will probably need slightly more.
Does anyone have suggestions on how to go about buying the right UPS? I only need help on getting the right VA/W capacity for the UPS, not the other features.