The question of speed when it comes to programming languages is as complex as a question can get. Java advocates can point to a lot of areas and claim to be fastest and they would be 100% correct. Ruby/Python advocates point to a different set of parameters and claim to be faster and they would also be correct. Erlang advocates then point to concurrent connections and claim to be fastest when dealing with hundreds or thousands of concurrent connections or calculations and the would not be wrong either.
Looking at the basic description of the project in question it seems to me that Erlang would be a perfect fit for your needs. Not knowing the details I would say that this would actually be a pretty darn simple Erlang program and could be done in a very short time indeed.
