Where do I find the php cli binaries?

You find the PHP version 4 binary at "/usr/local/php4/bin/php4" or in short php4.

[root@web2 ~]# php4 -v
PHP 4.4.8 (cli) (built: Feb 19 2008 13:12:43)
Copyright (c) 1997-2008 The PHP Group
Zend Engine v1.3.0, Copyright (c) 1998-2004 Zend Technologies

You find the php version 5 binary at "/usr/local/zend/bin/php" or in short php.

[root@web4 ~]# php -v
PHP 5.3.2 (cli) (built: Mar 31 2010 10:55:29) 
Copyright (c) 1997-2010 The PHP Group
Zend Engine v2.3.0, Copyright (c) 1998-2010 Zend Technologies
    with Zend Extension Manager v5.1, Copyright (c) 2003-2010, by Zend Technologies
    - with Zend Data Cache v4.0, Copyright (c) 2004-2010, by Zend Technologies [loaded] [licensed] [disabled]
    - with Zend Utils v1.0, Copyright (c) 2004-2010, by Zend Technologies [loaded] [licensed] [enabled]
    - with Zend Optimizer+ v4.1, Copyright (c) 1999-2010, by Zend Technologies [loaded] [licensed] [disabled]
    - with Zend Debugger v5.3, Copyright (c) 1999-2010, by Zend Technologies [loaded] [licensed] [enabled]

Note: We are always using the latest stable PHP versions of each major PHP branch once they have been evaluated from eZ Publish.