432438 PHP code change in Realestate listing website

We have a real estate listing website (very easy and simple - idev PHP REALestate- which allows anybody to register without problem and then post listing. Admin has the control to keep those listings active on posting or pending. Once free posting is appearing then the registered user can upgrade to paid listing and paypal is enabled with IPN automatically upgrading the listing. What we want is 1)On the registration page a math type captcha(11+2)= 2) Check the registration script and make it accept only valid emails (error message for invalid emails). 3) The core requirement of this project is, after posting the listing it should present the screen for payment and only on payment the listing should be shown as accepted and should be enabled rather than the present accepting of listing without payment and the upgrade option. 4)We want the free affiliate script JAM installed integrating the above script. 5) If you could give a new look to the script with css or any code,header,etc. that would be an advantage. (Any database changes to be taken care of) Additional: I dont know whether it is possible or not If you can with PHP code to grab real estate listings on the web with photographs for that particular region or city for search terms to be specified on the fly- showing them on our pages for that city/region along with paid listings - the email and contact should be changed to ours. And the original email of the seller should be stored in relational database. If any body enquires over the form to be created by you, then it should automatically email the original lister saying there is a prospect generated by our system for their listing, if interested , we can send the details for a cost of $x and if they pay by paypal then it should automatically email them the contact [login to view URL] MYSQL. This is in addition to the existing pay per listing model. At the end of the project we need the entire list of files and code changes you did for us in a text file to be sent to us so that we will replicate in two other sites. Thanks in advance for bidding