So I have 3 little pumps from greatbreweh.com, 2 ifm flowmeters (eBay), couple solenoid valves, and 10 motorized ball valves (eBay).
I've been playing around in sketchup a little, I'll modify the P&ID and post it as well later.
Edit: Here's my napkin-sketch of the process piping to accompany the above piping sketches.
I will be fitting bottom drains on all three vessels, and the Brew Kettle will also have a side drain. This will allow me to whirlpool, and then extract from the side when I pump off the hot wort to the chiller.
I can drain the debris automatically when done. I'm thinking of using a 2" TC on the bottom drains, and then using a 2" x 1" concentric reducer maybe. This should make the bottoms of the kettles drain well.
It's pretty simple, and offers a great deal of flexibility. I am planning an automated CIP cycle that will have it's own vessels and pump etc. The hot PBW or whatever I wash with will pump through sprayballs in the MLT and BK, and return through the CIP drain. Once the vessels are washed, I'll close the CIP drain and capture a volume of the hot wash solution and do an automated line wash which will flush all the wort lines with hot wash solution. Open the drain back up, let the CIP balls run for a little longer to re-flush the kettles, then automatic rinse cycle using the same idea and optionally.
I may use a second CIP tank with StarSan to circulate through the system after the rinse. It would also allow me to run a StarSan cycle before starting to brew.
I put some manual ball valves at the other two lowest points of the plumbing, so when clean it can all be drained.