What is the best payment tool for non-profits?

I'm creating a form for a non-profit event and not sure what the best payment option would be for easy registration with minimum fees taken out. 

I personally suggest Paypal standard.

You can check out the following guide on how to integrate it on your Form https://www.jotform.com/help/391-How-to-Integrate-Form-with-Paypal-Standard-

Thank you