Need a PHP email reffer script

[Stever]

Im lookin for someone to build a, or adapt their current, email referal script for me.
One where the user submits their info and email address, the email of a friend they want to send my stuff to, collects some other data, and sends by email my stuff to their friend. Sends a confirmation email to the refferer with an opt-in/out feature to recieve future emails.

I got lots of questions about what can and cant be done thru this setup.

Like:
- how do you send a generic text email for those email clients that cant open html pages while those that can get the html version.

- can i take the persons name out of the data field and place it in the email subjectline to give it some credibility so friends read it, even though it may be a form of spam.

- collect ip, and country, maybe other data.

- can i use the ip data to limit the number of times a user reffers to multiple friends?

Is this a simple or complicated task for a php guru?

hit me up

p.s. This is not for porn. Another idea I'm workin on