Need help with an affiliate program

Not sure if the title is right for this post but will try to make my question as best as I can.

If I know of a niche where people make products but have no interest in marketing I know I could make some money. These people have really no interest in marketing. They may have a small website, make their products and sell or give them away to each other. I would like to set up a program and market these products. They could put them on my site I set up for this and for every product sold I get a percentage and they get the rest.

I would need to have it so that they could track their own sales and I need to keep track as well. Some of them sell their products pretty cheap which could be upped a little. They need to be able to keep track of their sales and get paid. They could get paid right away or after a certain amount is reached. I know they would not have any problem making money from their products but they don't want to put in the time to market them. It would take to much of their time away from what they do, this is where I could come in.

How could I do this? Is there some sort of program that could automate this so that when a sale is made their end goes into their paypal account and mine to my account and that would allow them to track their sales and me to track the whole deal easily?

Thanks
Scott