Almost all of the S/T processors are just underclocked/undervolted versions of the standard models which you can do yourself fairly easily.
There don't seem to be T models at standard vendors but the S models can be gotten at places like newegg, but they really don't gain you anything now that turbo is on all the models. Ironically, while the K models use more power at peak, Tom's determined that they use less total power to accomplish a specific task, so you are likely better off just undervolting a standard chip.
http://www.tomshardware.com/reviews/core-i5-3570-low-po...