I have a late 2011 21.5" iMac that I run a second monitor via the only Thunderbolt port. At some point I will want to try using a SSD external drive as a boot drive but I do not want to loose my external monitor. Does anyone have experience with this type of setup and if so how well does it work or not work?? I'm concerned that as I have intermittent problems with the external monitor not waking up which requires that I pull the cable out of the back of the iMac that this might really cause horrible problems with an external drive. Obviously the external drive would need to have a second port to allow daisy chaining.