Sell domains from multisite, but use WHM on external server

Hi, I am creating a multisite network hosted on a VPS without cpanel. The VPS has a dedicated IP. After the domain purchase the client can point the domain to my IP and everything works good.

But I need to sell domains from the wordpress admin and set up the domain DNS automatically, I understand that´s possible with your plugin. However, your domain mapping plugin asks me the WHM url. I guess this is to assign the name server or modify the domain DNS after the purchase made by the client.

Is it possible to have 2 servers, one for the multisite network and other for WHM to manage domains DNS?

The thing is, the server where the multisite is hosted uses Ubuntu and cpanel doesn´t work with that OS and I dont want to move wpmu to another server because it might break. So it would be best if I can continue using my current VPS and set up WHM on a new server.