I have a MacBook Pro and a Mac Mini and will be getting an iMac next year. I'm worry about theft so am looking into getting one of those security locks. I prefer one that is a combination lock. What is a good brand to look into? I've heard mostly about Kensington but when I went to Apple's online store there were a lot of concerned about these damaging the laptops, not holding well, etc. Is there a specific Kensington lock or another I should look into?