If you know how to used Microsoft Access and Excel, you could keep track of the serials using an Access database and process the commisions in Excel using some simple calculations, or just use Access to do it all. It is hard to find an off-the-shelf program that will do everything you want. I have found that it is much easier to become really familar with the two programs I mentioned earlier, then you can customize documents that will end up saving you a lot of time and money.
