Hi @PatrickConway
Thanks for contacting us.
My first advice would be to create a Business account (or upgrade your personal account). This will give more solutions regarding processing payment/donations within your Website/Business.
Ref: https://www.paypal.com/us/smarthelp/article/how-do-i-upgrade-my-paypal-account-type-faq900
We do offer a solution within your PayPal profile, where you could create a Donation button and add on the step 2 of this process a list of "programs" (reasons) for the donor to add when making a donation using the button.
Button tool: https://www.paypal.com/cgi-bin/webscr?cmd=_button-management
Thanks,
