Most of the time you are able to team using the built-in LOM (LAN on Motherboard). Though, it is recommended that you have at least one "server" adapter in the team.
You might look at the Intel(R) PRO/100 S Server Adapter. (http://www.intel.com/Products/Server/Adapters/PRO100S/PRO100S-overview.htm).
Which OS are you looking to create this team in?