Plan to get a SSD recently and put to MBP 15 (2012). Option1: SSD to replace the DVD-ROM Driver, Original HD still at original place Option2: SSD to put to original HD place, and original HD to replace the DVD-ROM driver. SSD will be the system disk. Question: 1. Which option should choose? What's the pros and cons? 2. What kind of DVD-ROM bay should be purchased? sata3 interface or something?