One wouldn't have to keep hunting for ZPM's one wouldn't need to leave the city at important times just take it with you. If your new sensors detect a hive coming do one better, don't turn invisible, leave the system. Park yourself In space for a week or a month or so. Go to a different planet. You still have a ship that is huge, which will amaze any of the locals, and with upgrades will be able to fight off anyone. Asgard weapons or modified drones. Should do the trick. An interface from a puddle jumper taken apart would give a command / bridge chair drone firing and aiming capabilities.
Mid way station might even have a facility that makes tauri tori? Speced jumpers. Rail guns, and missiles, can't go invisible but they do have a shield.
The 302b gate ship with folding wings, and troop compartment and digital and crystal tech that even low level people can fix, maybe even military.