I have worked on installing iDevAffiliate on multiple websites and am still working maintenance work for some of them. I have successfully integrated PayPal with iDevAffiliate, as well as other carts and payment methods. I can also fully customize iDevAffiliate to match the needs of your business.
Other than iDevAffiliate, I have worked with many other affiliate programs (like PAP, HO, CJ...), and you can read about it on my profile. At the moment, I would recommend sticking to iDevAffiliate or, in case you really want to, you can switch to Post Affiliate Pro (PAP).
The integration can be completed within a few days, and I am guessing it shall take me several days of work for it, just in case something is wrong in the coding, or the installation was not performed properly. I work weekends, so you needn't worry about time. I am trying to make a breakthrough on this freelance website, so I am very eager to start work.
If my offer is of interest to you, please contact me over Freelancer so I can provide you with Skype or other contacts.