You have cups-nosystemd, ghostscript-nosystemd, cups-pdf-nosystemd on the obarun repo. Service are available under the name cups-s6rcserv or cups-s6serv.
Tell me if you have any trouble using it.
So, for the easy way:
$ sudo pacman -Sy cups-nosystemd cups-s6serv
$ sudo s6opts enable cups
enjoy
note : to see if a package is available on obarun repo just type this on shell :
$ sudo pacopts origin
obviously pacopts need to be installed first :D.
pacopts compare the package installed with the obarun repo, if you have installed a package with arch repo which is available on repo obarun too, pacopts alert you :)