Actually i have most of the client websites are PHP or Wordpress based.
But, still 70-80 websites are using .net MVC framework.
So choosing Windows Server will solve problem for both. But, on Centos we can run only PHP, HTML based websites only.
However, I'm not sure what level of support KH will offer you with this setup. For example, I didn't want to affect my dedicated server so I set up a separate server on one of their VM's for a ColdFusion application, I don't expect any support beyond what they initially setup. If you decide to try it you may want to first test that MVC setup on a cheaper VM before committing to the more expensive dedicated server.