I am looking particularly at the Postmodernists such as Derrida, Foucault and their colleagues. Also, if you could recommend some biographies or histories of that group, it would be appreciated.
This is an interesting question, and I’d like to give it a go answering, however there are also a couple issues with answering it at present.
In your question you have referred to the French communist party, and to ‘Stalinist academics’, and then specified Foucault and Derrida. However neither of these philosophers could be considered Stalinist in any stretch - Derrida being at odds with the party, and Foucault’s criticisms of power systems being quite opposed to the likes of a Stalinist model of governance.
As such, are you wanting to know more about the political philosophies and beliefs of Foucault and Derrida, or are you wondering more generally about other French intellectuals of the period who were either supporters of Stalin (or post 1953 the Soviet system) and/or those who may have had links with Soviet intelligence?