FYI, for installing things most of those distributions will provide you the SSH commands you need to run in their installation documentation.
Ioncube has no installation (you just edit your php.ini file to point to the loader)
Installing eacceleratormemcache installation--If you just need to be able to access memcache from php, you can install via PECL
--Also, you prob wouldn't want to run memcache on your web/db server - memcache servers are generally separate, and house several GB of memory and do nothing but serve cache requests
For PHP modules, you don't need to install them, you simply edit php.ini to enable them.