If you're deciding on Plesk vs. ServerPilot, here are some things worth considering.
ServerPilot is the best hosting control panel for developers and businesses running their PHP applications on cloud servers.
Plesk is for hosting companies selling shared hosting as their primary business. It is also sometimes used by developers who are hosting client websites on VPSes when Plesk comes with their VPS.
You can sell hosting on top of ServerPilot using HostLaunch.
If already have mail hosted using Plesk, you can continue to use Plesk just for email hosting and move your apps to servers managed by ServerPilot for ServerPilot's better web hosting configuration. Alternatively, if you don't have mail hosted in Plesk already, there are other options for hosting mail.