Our servers for this lab have the following configuration.
Another benefit is, arguably, Linux can be more secure as there are fewer known vulnerabilities. Without complex third-party packages, BIND domain zones may only have a single master, unlike with Windows DNS.
A Windows name server in an Active Directory environment is capable of multi-master, giving you much higher availability.
A Linux BIND server is a very light-weight and fast DNS server.
You will not need a lot of hardware to power it in medium to large environments.
I do not include hardware specifications, because those are strongly based on uniqueness of your environment.