How to integrate Membership with idevaffiliate?

I need to integrate the membership plugin with my affiliate software (idevaffiliate). I'm going to be using Paypal Single Payments Gateway for this product, since it's a one-time payment. So here are my questions at the moment...

1) idev has two integration codes, one for buy now buttons and one for subscription buttons. I'm guessing that since it's a single payment, this would be using a buy now button. Is that correct?

2) The code is to add two (3 if subscription button) hidden fields to the button code. Where would I be looking to add this?

3) One of the hidden fields has a name of "notify_url". This won't impact anything in the plugin, will it?