I would definitely recommend going with a
Smart-UPS 1500 over the
RS 1500 version. They're much more reliable units and offer much more industrial protection. The RS version is a home use version while the SUA1500 is more of a data center unit. For Apple applications the SUA1500 is much more reliable, will offer a greater run time and much better power filtration capabilities. If budget is not an issue, you can always go for the top protection with the
SMT1500 which is the newest model of the 1500. There's no point of trying to buy the cheapest UPS as it just won't provide the required protection and will end up leading to some sort of data loss or hardware loss. Might as well get proper protection.