It's so hard to think of an ideal five-day stretch. Conques to Cahors would be fine, but I think four better options would be:
Le Puy to Aumont-Aubrac (or Nasbinals): Because it's always nice to start at the beginning.
Aumont-Aubrac (or Nasbinals) to Conques: You cross the Aubrac plateau, and stop in some wonderful medieval towns.
Figeac to Cahors via the Vallée du Célé. Just stunning. Lots of up and down, but it's worth it.
Lectoure to Eauze. You're in Gascony, the culinary heart of old France, and walking through Armagnac country here. That's enough