Damn, it's really hard to follow this on 4 different forums
About peltiers, this is my post from CN, explaining how I assembled my own 2-stage TEC:
"Today I tested my DIY 2-stage peltier module. For the first stage, I cut TES1-12704 30x30mm module into 20mm width. On top of that I glued with thermal conductive epoxy another module, 20x15mm TEC1-2304. Both modules are connected in series. Results (without CCD) are promising, with 8V power supply, module draw 2 amps and can easily reach 60 degrees C temperature difference. 15 watts of generated heat I can easily dissipate with my CNC milled housing.
CCD will be thermally insulated and in a Argon filled chamber. Now I am worried about thermal sinking through the CCD pins...
More tests will follow."
So, with peltiers we must concentrate on efficiency, not on a power. CCD power dissipation is next to nothing, main thermal losses are thermal sinking through pins, and through convection. Convection problem can be solved by thermally insulating whole cold side, including sensor. Heat transfer through pins is much harder to reduce. On my next build my plan is to use FFC (flat flex cable) to connect sensor with PCB. That will completely eliminate thermal sinking.