Hey guys, After a lot of deliberation, I've decided on a 27" iMac for my photography business and am picking up a used one tomorrow. The problem is it has no SSD and I can't go back to anything but after using one. As most of you know, they're a must-have. My question is is the Seagate thunderbolt adapter the cheapest option to get an SSD running as a boot drive? I know I can do USB 3.0 but I've read that it can be hard on the processor and I'm not ecstatic about spending $100+ for a Seagate TB adapter and another $30 for a TB cable! Insane!