Thanks guys,
One of my part-timers emailed this to me last night and I though I would share it with you. If you hear of any more arguments or have an email address of someone that knows more, please pass it on. Thanks for the comments.
Here are the key points that you may want to focus on.
1) ColdFusion is MACROMEDIA's server side programming language. Macromedia is the only group that actually updates the code. Because of this, It advances at a less faster curve than PHP.
2) Running coldfusion requires a hefty server. ColfDusion actually piggybacks itself on JSP. Because your are technically running 2 server-side languages, (ColdFusion talking to JSP, JSP executing commands) it not only creates server bog downs, but can actually increase troubleshooting for any specific error.
3) Implementation cost. ColdFusion MX (the only readily available veriosn of CF) costs a little over 1G. PHP is free.
4) More apps for PHP by far. You never know when you will want to add functionality to a website.
5) PHP is faster. Each re-release of the PHP engine generally improves execution spped exponentially.
6) Only Macromedia supports ColdFusion, and then only partially. Custom scripts are generally excluded. With PHP, you have a world of developers to ask, and documentation that would fill the pentagon to go with them.
7) Implementation - we all know that with Linux, installing software can be treacherous. I once worked with a Cobalt Raq550 and had to call up ColdFusion support to see if it would be possible to put coldFusion on the server. They said it should be ready to go out of the box. Upon more research, I found 2 people that had been able to do it, only after changing out 5 or so linux modules.
Let the customer know that, yes, ColdFusion can do all the things that PHP can do, with the exception of sub queries. However, if they want to spend the cash on an overpowered server, waste time getting it implemented, and only have support coming from one main area that ColdFusion just might be the package for him.
However, if the customer is looking for a server-side script that is designed with each release to be faster on ANY machine, with a development base of world wide programmers, and more applications than I can dream to count that can be installed at the blink of an eye, well, they just may want to think twice.