An excellent 4-2-5 playbook that doesn't get nearly the same attention as the TCU or Boise State playbooks is from Villanova in 2004. Joe Trainer, the current Rhode Island head coach, was the Nova defensive coordinator. The '04 Wildcats were 7th in Div. I-AA is scoring defense (16.2 ppg).
The playbook also contains position manuals for DL, LB, and DB at the end. The secondary manual is excellent. If you are a split field safety 4-2-5 team it is a must read.
2004 Villanova Defensive Playbook