Something closer to the Scandinavian one , the traditional one or no prison at all?
I'd go for an approach that had no prison at all for minor offenses, maybe just community service. For moderate offences, something like the Scandinavian ones with a large focus on rehabilitation. For life imprisonment, a remote island like in the movie No Escape. However, in the movie only half of the island convicts formed a community and started farming while the other half went all Lord of the Flies. I can't remember why they also had a futuristic rocket launcher on the island. That's the 90's for ya. It certainly not as easy as it is in my head. No idea how I would factor in the large number of inmates with mental illness.
You can't cure/help a psychopath though, and he wouldn't even want you to.
I'm with you there. ABOLITION, ABOLITION! BORDERS, BOSSES, WARDENS, PRISONS! ABOLITION, ABOLITION!LANDLORDS, COPS, POLITICIANS?