Back from another holiday (I call it the Arnold Rimmer technique) I've been trying to collect, rework and refurbish my thoughts on web-based Kerberos stuff in a personal Wiki.
You're welcome to peruse it with the usual disclaimers that I'm frequently wrong; unlike most people-friendly wikis, this one's read-only unless you're me.
So, feel free to poke around; there might be something useful in there somewhere.
I think there's a definite market for a kerberos configurator - a drag-and-drop layout tool that lets you draw your network, and have it fill in the SPN registrations you need to use. When I get some time (ah, hahaha! I am so dry!), I might take a look at it.