Installing SSD on iMac iMac, 27 inch, late 2012 3.4ghz | MacRumors Forums
maxupgrades.com: Single SSD Drives kit for iMac 27 inch 2012 Models with SATA Blade SSD Module / Heatsink/ Power Cable and DATA Cables for [SSD + HDD] with iMac Adhesive LCD Tape
SSD Upgrade Kits for 27-Inch iMac (2012 - Early 2013)