maxupgrades.com: Dual SSD Drives kit for iMac 27 inch 2012 Models with Blade SSD Module with Heatsink and Power and DATA Cables
Amazon.com: OWC 2.0TB HDD Upgrade Kit Compatible With 2009-2010 iMacs, Includes: Thermal Sensor, Tools, 2.0TB Hard Drive : Electronics
My 12 y/o son is so excited. Found him a pristine Mid-2010 27" iMac for $100. Going to give it the SSD upgrade but he's stoked to start recording music with it :
iMac Mid 2010 SSD Upgrade - YouTube
How to Install a 2.5-inch SSD in the SSD Drive Bay of a 27-inch iMac Mid 2010 (Updated) - YouTube