I recently came across a post that said Microsoft is discontinuing the external public facing website on SharePoint and we'll have to use some third party app. I have to create a a public facing website for a client on SharePoint itself,what should i use?
It is correct that Microsoft have removed the SharePoint public sites. Instead they suggest to get a public website from a third part provider.
The official announcement from Microsoft states the following:
As part of the evolution of the Office 365 service, we periodically evaluate the capabilities of the service to make sure that we’re delivering the utmost value to customers. After careful consideration, we concluded that for public websites, Office 365 customers would be better served by third-party providers whose core competency is public websites. Therefore, we’ve made the difficult decision to discontinue the SharePoint Online Public Website feature so that we can focus our efforts and investments on delivering capabilities in Office 365 that will bring more value to our customers.
I think when you use on-prem you could still use it for a public site. I don't know about the licensing. There used to be a special license for an internet facing farm