associated projects selling training material

Hi there

I'm the liason of the YafaRay project. Our project is rather small although we have a relatively broad user base.
We are doing about 7.000 downloads a month.

However, the fact is that donations does not work for us. it is more dificult for desktop software to get support from the big guys.

This is not a big issue for a project with small needs, but our project faces now critical times and we would like to organise a first "code sprint" to get together and strengthen
our bonds.

Selling training material would be an option for us. We are not sure whether is going to work but at least we would like to try.

We would like to ask whether we can still use SPI protection for the money raised by those sales and how to accommodate a checkout process
from an e-shop within the current "click & pledge" framework. I don't believe it can be done.

For instance, can we use Amazon Payments or Paypal under our responsabily but draw funds from those and get them directly to our SPI account?

Thank you for your comments on these regards. Greetings

Alvaro