46402 Purchase Digital Goods/Serial#

I am a PHP programmer myself, but do not know PayPal IPN and instead of trying to learn it for one script, instead I would just like to hire someone to create it for me. I have created a PHP script that uses a license key, and right now people have to e-mail me to purchase it, but I would like to automate that process. I would like users to be able to purchase the script, and enter in their domain name that they will use the script on into a form, and then they make the payment, and then are delivered the script and a license key (which is generated by a PHP function that I created). I run phpBB on my site, and have already created a usergroup where users can download updates for the script (as they are free) if they are a member of that usergroup. So, I would also like this script to be integrated with phpBB and detect the user and then upon purchase, they are automatically added to the usergroup. I would also like people to be able to purchase an additional license key (just the key, not the script). I would also like people to be able to purchase "copyright removal" for my script (requires no delivery of actual goods, just a note on an order history page stating that they are allowed to remove the copyright). Also, if a user purchases 3 total licenses (the first copy of the script + 2 additional licenses), they are given free copyright removal. I would like this to be shown on the order history page (and it does not matter when any user purchases the script and additional licenses, they can be purchased together or separately). There needs to be an order history page that allows users to purchase additional licenses (where again, the user enters the domain name and a license key is generated), and purchase copyright removal if they have not already done so and if they have not already earned it for free (see above). I would also like to be able to add more digital goods to sell (such as templates or addons). The templates will have multiple purchase levels that I need to be able to set (the levels will be when a user wants to purchase the template to use on 1, 2, 3, 4, or unlimited sites. there also needs to be a "unique" option, where if a user purchases a "unique" template, it is automatically removed and never sold again). I would like this script to be completely unencrypted so I can make small adjustments myself if need be. I listed this project before and it fell through. Please, serious coders only.