You should take a look at www.nethserver.org it has already integrated owncloud 9.x with one click install, making a module also for nextcloud would be very cool and interesting. NethServer’s straightforward to install and administrate, all through a modern webUI and based on CentOS
I’m happy to see this new project, I have waited for @jos’s next move for a while. Hi @jospoortvliet 
Disclosure: I’m the NethServer community guy 