Integrating with 3rd party Fundraising software

Site URL: https://raeraeoflight.org/

Hi - We have a small, new non-profit and we are working on new fundraising event.  I would like to be able to have additional functionality around the registration / donation process for the event and need more functionality than the donation block allows.  We'd like to have team sponsors, individual sponsors, a live fundraising progress widget, etc.  Does anyone know of fundraising software that integrates with squarespace that would allow this kind of functionality, and not cost a fortune?  Thanks in advance.