If I'm being taken to court over a debt that is past the SOL, what type of documents should I bring to adequately defend myself?

4 years correct under 42 Pa. C.S. 5525(a)?  You need to understand when the statute begins to run from (the date the calculation starts from). Since the creditor has 4 years to file suit from the date of the last activity on the account, which almost always means the last time the debtor made a payment. If the debtor made no payments at all on the account, the Statute runs from the date that the first payment was due. Some times certain events extend or "toll" a statute. Moving out of state is one of those events. So what you need to bring at the very least is proof of your continued living in PA and the date you last made a payment.  Remember to raise the statute of limitations as an affirmative defense on your answer.  Good luck.