If you are working as a CFI, you don't need to waste time going to a dedicated flight school for your CFII. The CFII checkride is pretty much an IPC from the right seat. You obviously know how to study for a checkride at this point.
Read the PTS, study the oral exam guide, and spend a day reviewing before you take the written. Call an examiner to get a checkride scheduled and find a CFII who can give you 3 hours of checkride preparation.