We have added a new feature to v6 to set a template for use with a specific language already inserted into the software. You only need to make sure the language is actually in the system within the LANGUAGES admin tool. Once the language is there you only need to set the language to a specific template set within the DESIGN > TEMPLATE SETS admin tool. From then on when a client choose that language on the client side they will see the template set you have associated with it.