Thanks Jazz - there are certainly plenty of AM882's listed on there. Curiously no EM806's though. Sounds like I shouldn't be worrying about non genuine ones, which is good to know. I've not yet used Ali express, so was just a bit cautious. I have however bought kit from China on eBay, so not complete beginner in this!

So something else occurred to me. I'm more then happy that the 80v drive is the way to go for the 68v PSU router. For the mill - which for the record is going to be something along the lines of a Sieg X2 conversion using 2Nm steppers - does this require such a high voltage drive? My understanding is that it won't need the feed and rapids speed that a router does, and so a lower voltage for the drives is more in keeping. And that in turn means less expensive stepper drives. Or have I missed the point?