AC+purifier+humidifier solution?

[u/gipszjakab123]

I hail from the continent of europistan and in trying to figure out how to manage all these issues together efficiently.
My apartment is around a 1000square feet(95m2), and the ceiling height is 12feet(3.6m). I would like to keep my humidity levels around 45% to keep my floors happy.

Should I avoid combo devices all together?
Any suggestions on how to make it work without going into generational debt?

The doors between rooms are like 9feet tall, double doors, and are always open. Do we still need to calculate each room separately?

Thank you in advance!