A payment can have different status.
However, I'm not convinced these payments need anything Signup Status doesn't already do.

on this page... admin/content/signup_pay
lets display the signup status of the individual.
This is particularly useful when a registrant is paying by cheque, as this payment wants to be recorded as not paid.
My opinion is that we don't need to record the status of the payment separate from the status of the registrant.

Peace