I am not able to find the template for publications in Proceedings of the IEEE.
Here is an example: A Survey of BGP Security Issues and Solutions
He said journal. No template will give you the Proceedings look because it is set in a commercial font: Font Bureau Whitman. It is the IEEE's flagship publication, so they want to jazz it up a bit.
However, you could approximate it with a transitional typeface like Charter or Utopia.
I do not believe that there is currently a LaTeX template for the current style of Proc. IEEE shown in your example, but there was a class file written by Michael Shell that implemented the previous style of Proc. IEEE (which was used by all the IEEE Transactions journals as well): http://www.michaelshell.org/tex/ieeetran/
Gregory Plett also created a class file for the previous Proc. IEEE style: http://mocha-java.uccs.edu/ieee/