watts (Joule/second) is a measure of energy/time, it is used to measure power. When we talk about the number of watts from the processor, it is the heat output that we talk about.
In the Peltier's case, the number of watts is the heat pumping rating of that peltier. (It is not the power draw of the peltier, as that is quite a bit higher than the peltier's heat pumping rating. For example, a 220w peltier's max rating is something like 15v, 24A, which is 360w that it draws.)
For peltier cooling, people have found that the peltier's rating should be around 2x that of the CPU's heat output. This means that a 220w peltier can be used to cool CPUs with up to around 110w of heat output, if the peltier is cooled adequately.
The setup you're thinking of would work, but if you air cool it, you'd have to use it on a processor of 80w or less, as swiftech has a peltier heatsink very similar to what you are planning, and this is the performance graph of it:
http://www.swiftnets.com/assets/images/products/mcx462/operating_range_chart.jpg
As you can see, even with a 80cfm fan, once the CPU's heat gets above 85w, the temperatures just start shooting up. You can go here to work out the heat output of your planned overclocked CPU:
http://www.benchtest.com/calc.html If the heat output is more than 85w (likely), it would be best to abandon the aircooled TEC cooler idea, and get a peltier supporting waterblock.
