Many thanks for all the feedback!
And a happy xmas,
A

You have to be explicit about Mr. Li exchanging the analogue ET meter with a digital one. No problems, just let him know before shipment.

Just to confirm my understanding, the digital Environment Temperature (ET) probe replaces the attractive analog thermometer, but may be installed by Mr. Li so that you can include ET into your display on the Artisan software provided that you also order the Center 304 digital thermometer which accommodates up to 4 sensor inputs. Subsequently, can the analog thermometer and the digital probe be exchanged at any time?

Yes, sort of and yes. Mr. Li will install whichever you prefer. You can use a Phidget instead of the datalogger. The upside of using a datalogger instead of a Phidget is you will still have the temps displayed if the computer side fails on you. I'd say most people nowadays go with just the Phidget. The analog thermometer and digital probe can be swapped any time. Be sure to be very clear on what you want when you make your order.