So I picked up the Boxster today. The shop did a pressure test, and everything is fine. Strong pressure, no leaks. The water pump and all coolant lines are dry, no leaks. So that's all good, I think.
They topped things up with Porsche OEM coolant, and gave me the rest of the gallon so I'll have some if needed. I've got the car safely back in the garage with cardboard under it, so I can see where any leaks may happen while I'm out of town for the next two weeks. Hopefully, no surprises.
I'll ask them about the brand of water pump they used, and the temperature sensor.
Thanks for the help, guys. I appreciate the education.
Dave