System Requirement for NAV

We are planing for the NAV that will be used by 3-4 users. The system will be configured only for Finance (GL, AP, AR and Inventory)

I want to know what is the Hardware sizing of a server, I want one single server to act as Apps/database.

What is the version of OS? Windows Server 2003 or 2008

What is the version of MSSQL?

Windows Server 2008 R2 with SQL Server 2008 R2.

How about the hardware? can one server be used?

RAM, Processor, Disk etc.