Suppose i purchase a WD MyBookStudio II edition... 1. Is the 6TBdrive solution, a combination of 2x3TB drives and the 4TB solution, a combination of 2x2TB drives acordingly? 2. When those drives (6TB or 4TB) connect with my Mac, how many drives are viewable to be mounted on my desktop? 3. Suppose i want to divide the 6TB solution to two drives (a 4TB and a 2TB drive) is it possible to be able to use one of the two as a TimeMachine drive and the other for storing purposes? 4. Will there be any possible issues if i do the setup described on 3? 5. Are there any suggestions for different brands but same specs?