151527 Need changes to PHP program

We have purchased a program called "Post Affiliate Pro" that needs some modifications done. We have the original code, but we need to modify the program to include some features. Things we need PAP to do: We would like to create different affiliate groups, preferably an affiliate group for web sales and a reseller group for brick and mortar tech shops. We would also like to be able to assign affiliates to a specific campaign. Currently if we have multiple campaigns then the affiliates are in all of those campaigns. We need to be able recalculate the totals paid to affiliates for performance rewards. For example, if an affiliate sells 5 to 10 units we would pay them a certain amount, but if they sell between 10 and 50 units then they will be paid more because they reached a certain performance level. What is happening now is that PAP will assign you the lower commission on the first 10 units, and then it starts assigning the higher commission to sales over 10. What we would like to do is have PAP recalculate the sales sold at the lower commission to match the higher commission once the affiliate reaches the performance level. So, if an affiliate is making 7 dollars per unit sold and then sell enough units to get 10 dollars per unit, then PAP should change the earlier commissions to 10 dollars. I would also like to look at what it would take to create our own e-mail templates. PAP doesn't have a "declined" letter. One other thing... When testing the system to get the e-mails, we found, that if you decline someone after they are approved, no e-mail is sent to let them know what happened and, the opposite happens when you reapprove them. We would like to make a way to customize email messages through PAP. Basically we are looking for someone who is very very good with PHP. Only clean, well organized code please. We will need to work closely with the programmer to make certain that all changes are working properly, and we only want someone who will stand by their work and will fix any/all problems that arise from their code. We will own all rights to the changed code, and NOTHING can be rebranded from this since PAP is a purchased program and not our own. Only PHP experts wanted.