ION RCS.
Pulsed Plasma Thruster RCS.

[[http://imgur.com/a/P9Pcc#0]]

Ion RCS Thrusters that use Xenon-gas and electricity for incredibly efficient RCS. Some limitations:
Has half the Isp of normal Ion engines.
One quarter of the thrust of normal monopropellant RCS thrusters.
Available in one-way linear thruster, 4-way ION RCS block and 4-way 45degrees ION RCS block.
Integrated to TechTree at ionPropulsion.

Pulsed Plasma Thrusters RCS
Each thruster contains a fixed amount of Teflon and uses this along with Electric Charge for incredibly efficient propulsion for small craft or maneuvering.
Some limitations:
Has roughly quarter the ISP of normal RCS thrusters.
One eighth of the thrust of normal monopropellant RCS thrusters.
Only linear thrusters are available.
Integrated to TechTree at advFlightControl.
* See (http://en.wikipedia.org/wiki/Pulsed_plasma_thruster).