If you want to create custom rpms and install then with the usual automated dependency management you’ll need your own yum repository. This is just the RPMS and metadata in the format of static xml files served by a webserver.

One of those things that just took me a lot longer than I expected…

Changing memcache port seems simple enough - just edit /etc/sysconfig/memcached and change the PORT value

BUT on a new centOS install memcache failed to start on any non-standard port.