PHP/MySQL email to SMS

I am planning a project where the user would click a button in Flash and if registered in database (if not, they would be alerted to register), a short message would be sent to their cell phone.

I understand this can be accomplished by concatenating the users cell phone number with @providersdomain.com see: http://en.wikipedia.org/wiki/List_of…_or_Web_to_SMS

We would need an array of providers addresses to choose the address format from the provider field in the database to be combined with the cell number.

I need help setting up the database for users to register and the database of providers domain address. Then, program the PHP to access the datain response to the Flash button event and send an email text message to the phone.

How difficult would it be to do this? I would appreciate a ballpark quote.

Let me know if you need any other info. Thanks in advance for your help!