Some good info, seems to match with what Ive got in the way of equations but its nicer to have it in words.

That peltier you mentioned (03140) seems a little obscure. Do you know where to get them from?

When I chose the peltiers I did (TEC12709) I was aiming for:

Highest current,
Smallest physical size (40mm - this was to minimise copper cold plate costs),
Being dirt cheap ($35 for 10 inc. world-wide postage, packaging and paypal fees).