Nighthawk WiFi 6 Mk63 mesh extension

[Mark42]

I have a Nighthawk Mk63 Mesh with a base station and two satellites. I am still not getting great coverage in some parts of the house and am looking to add more satellites. I see that there is an MS60 that should be possible to buy to add another satellite, but can't find any in stock to buy on line in the UK. Therefore is it possible to buy a different model of Netgear Mesh satellite that would be compatible with the current mesh that I have? 

[plemans]

No. for the MK60 system, you can only use the 60 series satellites because its a dual band system.  

The 80 series support using the 60 but not the other way around.