The 2m tower is perfect starting point for all your needs, whether it be inside or outside. Add extra parts later to reach higher or create long scaffolding runs and roof edge protection.
All parts are compatible between towers, just add the narrow single platform width end frames to create narrow single platform width towers.
The bolt on spigoit allows you to stack a narrow frame on top of the wide frame, which just allows you to have two different width towers and still have the ability to stack them together as a 5m tower.
The CORE1400 can be converted into a 3, 4, or 5m tower by adding additional parts.