As for the battery backup, get a Carrier Axxess 48V battery and splice it to the battery connect cable on the 7100. Skip a 'UPS.' The 7100 trickle charges the 48V battery - the CA 48V battery is MUCH larger than any found in any portable/minimal UPS such as an APC 1000.

A 7100 will run for about four to five hours without AC if fully charged, not kidding. It does take about three days to fully recharge. The built in 7100 trickle charger is very wimpy, but relentless. Won't even drop calls when you unplug the AC power. All for less $$ than any but the smallest UPS.