Assist Dip / Chin.

Pull-ups from the first session.

The stack works as a counterweight and not as a load: the more you select, the easier dips and pull-ups become. That means the two best upper body exercises there are become available from day one, and you reduce the assistance in 5 kg steps until you hang freely, the alternative is waiting two years for it to happen on its own. The machine is 2375 mm high, so measure the ceiling. The only machine people outgrow on purpose.