Webmin/Virtualmin Multi-Server Setup

Hello, New and first post. I currently have the following multi-server setup using ISPConfig:

• ispconfig admin
• web-sp (web and MySQL)
• web-us (web and MySQL)
• mail (email and Roundcube webmail)
• mail2 (backup relay)
• ns1
• ns2

I want to replicate this setup using webmin, virtualmin and Roundcube using WHMCS as the billing module. As far as I can tell from docs I should do the following:

• Install Virtualmin/Webmin on main admin server
• Install webmin on web-sp and web-us and add them as servers in Virtualmin, then add them as web and MySQL servers.
• Install webmin on mail and mail2 and add them as servers in Virtualmin and add them as email and relay servers
• Install webmin on ns1 and ns2 and ad them as servers in Virtualmin and add them as DNS servers master and slave

Can anyone confirm the above is correct and also link to any multi-server setup guides for Virtualmin/Webmin? I can't seem to find much info.

Thanks in advance. Richie