They're all old, check up on the cars, demand a testdrive (if you dont get a test drive it usually means theres something fundamentally wrong with it), see which car(s) is/are in best shape and decide then.
Out of principle i advice againt 80's french cars since they tend to break down a lot.
Maybe Motor City steel is the best bet. (Impalas are Chevy's though). Anyway, judge each car on its merits.