In reply to blackreaver:
While grateful for the recommendations I'm not certain we'll be able to accommodate a group of that size this summer. Reason is that we've moved ourselves into the main house (selfish I know!) We're currently converting a barn into another large place to rent but we can't guarantee that it will definitely be ready by the summer so we aren't taking bookings for it just yet. We have 4 smaller apartments to rent so maybe we have enough space for you all but you'd have to check our calendar at
http://www.chezarran.com/calendar.html to make sure. Another good alternative for that size of group could be
http://www.basecalames.com/ , which is also well placed for the climbing and run by English climbers.
In terms of climbing at those grades in August, the obvious single-pitch venue is Auzat, but there are plenty of smaller crags that can be fine in hot weather too, especially those a little higher up. As you get higher in the grades (mid 6s and above) there are lots more shady options on the shaded valley crags too. If it's cloudy then Calamès or Sinsat are very fine choices for all grades (but not in the summer sun). The limestone multi-pitch is all pretty hot in summer but the granite can be perfect. The Dent d'Orlu is the jewel and highly recommended, but I'd recommend slogging up to Bassiès too as it's a brilliant location.