@OJT8601 Hello, 

In theory, all the TP-Link powerline devices on sale can work together. In the real network environment, it would be better if we use the powerline devices with same powerline data speed in the same network. We can also use powerline devices with different data speeds together. Here are some recommendations:

So better choice is AV1000/AV2000. As far as I know most powerline devices are sold by KIT, so you could consider a powerline KIT of the same model, in a KIT both powerline units could work as powerline extenders. 

@Solla-topee 

Thanks for the answer.

So if I order a TL-PA7017P KIT, it will be compatible with my TL-PA7020P Adapters. Both are 1Gb.

Thanks again.

Have a nice day.

Regards.

@OJT8601 Good day, 

Yes, they are compatible and you could add new TL-PA7017P KIT into your old powerline network when they are under same power meter. 

Here is an FAQ that may help: 

How to add an extra Powerline adapter to the existing Powerline network by adding the powerline key on tpPLC Utility(new designed blue UI)?

https://www.tp-link.com/support/faq/1059/

@Solla-topee Great, thanks !