Thermoelectric cooling do u mean peltier or tec ?? .
Well thermoelectric (peltier) is too hard to use and eat a lot of power (watch your power bills
) . Currently, The Q6700 when overclocked has a TDP over 180w or over in this case tec is not so efficient . U have to get the most powerful module 467 w in order to get about 20-30 c cooler than the hot side . In addition, such tec will require a lot cooling power (the more u cool the hot peltier side the more cooler became the cold side) .
In this case u have to cool 467 w (from peltier ) and 200 w from your processor , witch is over 600 w (this is not easy to cool).
U will require a high end water block , radiator and pump in order to get decent performance (but in your case my be 2 radiators are required).
Just water will do about the same performance , deference about high end water or water+peltier is about 30c , IF under water u get 40c load than under peltier u will get 10-20 c .
Note using peltier u will get a constant 476 w witch will increase your power bills .
In addition, Cooling peltier with air cooler is too inefficient .
For a reasonable price make a small water chiller or get a Phase change system (second hand) for 400 or 300 $ .
A lot more efficient , colder temp , less power requirements , easier to use .....