VMware Announces New Product for Apple Mac OS X Users
New Intel-based Macs will be able to Simultaneously Run Mac OS X, Windows, Linux, NetWare and Solaris
SAN FRANCISCO and PALO ALTO, Calif., August 7, 2006

http://www.vmware.com/company/news/releases/mac.html

Certainly your customer will need to by a Windows installation. It is also possible to convert a physical Windows computer into a virtual Windows computer. Though while I used this option for VMware Windows server, I cannot confirm that it is available for VMware Mac Server.