If he cannot afford to hire an attorney, a public defender will be appointed to him when he is In Court tomorrow. They have many excellent attorneys who will be able to handle the extradition issues.
Pro bono is short for "pro bono publico," which means "for the public's benefit." A criminal case is not a "public's benefit" case.
What you want is a public defender. The public defender's office represents people who lack the money to hire an attorney of their own in a criminal case. Just ask for one at your first time before a judge.