If you want to make sure you are getting the correct remote for your system, you can double-check your system using the serial number with our Product Identifier, or by calling your local support team. They will be able to identify the system and even order the remote you are looking for with you. You can find the contact information at this link, by selecting your country/region and then the 'Contact Us' option at the bottom of the page.
For the Cinemate GS II, the remote you would want is THIS one. It is described as being for the Cinemate 1SR in the name but if you look at the compatible products it is for the Cinemate GS II as well.
I hope this helps! Let me know how your search for a new remote goes!