Picked up a used 2011 i7 Mini that I am fixing up (missing a few pieces). My plan is to replace my time capsule and use the mini as a server for time machine for my other two Macs and as an itunes server (wouldn't be used for anything else). I would like to have two mirrored raid drives. My question is it better (speed, reliability, etc) to replace the internal HD with 2 larger capacity drives or add two external drives via thunderbolt (only usb 2 so I am guessing not worth it?). This server will be headless and near my network equipment. Any advice would be greatly appreciated. Thanks!