SQL Server 2014 Standard Ram and CPU
Per Brent Ozar Unlimited (linked below), the recommendation for SQL Server Standard 2014 is 192GB RAM. SQL Server will only use up to 128GB of it and the rest is to accommodate the overhead of OS and other processes.

This being said, 64GB may be far more than necessary to allow for the of SentryOne and the IIS application overhead.

How Much Memory Does SQL Server Need?

I believe that, for the cores, you must license each core that is allocated to the VM. You can limit the CPU's using the CPU page on the Server Properties.