Domaine de la Faurie, just off junction 56 of the A20 is a lovely site, with a pool. The site is at the top of a hill, with great views, and it's full of flowers, shrubs and fruit trees, all named. The site buildings are those of an old farm, and it's just delightful.
My old Michelin Atlas shows a tent symbol for campsites which are referred to in the Michelin Camping Guide, which is why I keep the Atlas, and there are sites just off the A20 at Payrac, Souillac, Donzenac, Uzerche, Masseret, and Pierre-Buffiere, if that helps at all.