For this proposed scenario I would use just three servers with Windows 2008 R2; a Filing server, an Application server, and a Monitoring & Threat Management server. I feel that Datacenter would be the best option to use as it is more cost efficient and provides reliable support by offering an increased number of processors and increase RAM as well as failover clustering. This also offers key features for power savings, manageability, and helps with allowing workers from remote locations to use and access company resources.
The Filing server will allow us to create files able to be accessed by different people from different locations. We will have increased ease of control over access and permission to these files as well as setting up partitions for allocating resources for saved data properly. Server Message Block (also known as SMB) to access the shared folders. This server can also be used for our printers so that we can set up multiple computers to print to specific printers.
The application server will give us an environment we can use for running server-based business applications for our company. This will allow users to access applications through a web page that is hosted on the server. We can also use this as our mail server by installing Microsoft Exchange. This is a mail server as well as a contact manager program that runs on Windows Server. With this users can get to their email using multiple email clients including the popular Outlook.
Finally the Monitoring & Threat Management server will allow our lead IT guy to manage and monitor the servers. There will be a remote access feature so our IT support can monitor these from different locations. This will allow for a better way to see any type of breaches in security.