Just wanted to give a general thank you to all list members for their 
input. Pressed by time, I eventually used a string quartet version of 
the M:I theme as the opening music, other string covers of popular tunes 
(such as Kronos Quartet's amazing "Misirlou Twist") and bits of the 
Barry Lyndon soundtrack to get some harpsichord in there.

The 1757 spy team was made of Charles-François de Broglie, a noble 
colonel as the leader, the Chevalier d'Eon as faceman/woman, Jacques de 
Vaucanson as the techie, Jean-Pierre Tercier as a the shade (they're all 
historical characters, but were "pulp-ified" for the game). Their 
mission was to free Giacomo Casanova from his prison in Venice and 
retrieve some important documents from him. As they failed and some 
prussian adversaries won, the closing theme music was a flute quartet 
version of the Mission: Impossible theme (Frederick The Great was big on 
the flute).

So there, thanks again for your time :)

Thomas