My wife and I have been assessing church planters together for many years. We use the process developed by Dr. Chuck Ridley over 20 years ago. (I was actually assessed by Dr. Ridley before I started Lake Hills Church in Castaic, California.)
If you would like to schedule an assessment for a potential church planter, you can find more information here.
Also, you might enjoy watching this interview with Ed Stetzer where he talks about the value and importance of an assessment process for church planters (click here).