Convert to PDF Web App

Hello, Looking for a Self Contained web app which allows users to uploaded a file and for it to be converted to PDF. The process should be very easy for the end user, 1) they Choose file from local PC and hit submit, Result 1 - File Type supported automatically converts the file showing a progress bar, Once complete auto downloads file/Provides link Result 2 - File Type Not supported - List of Supported file types is shown and log appended with file type which it is presented with. Ideally be able to host in a Linux Environment running Cpanel. It should also use open source software if required. As part of you bid please provide list of of Files types will likely be supported.