El Chorro is pretty cool and easy going place to climb at. Well it was in 2002 anyway. Good job you want to climb at 7c grades cos everything under that is polished pretty heavy. The walk to Mak is alright but be prepared to walk through a few active train tunnels. There was new area being worked on when i was there called Las Nubes; on account of it being really high above the gorge itself on the way to Mak.
Camping is pretty cheap but gets quite busy on weekends with people just wanting to go camping and partying. There is a hostel as well which was nice and fairly cheap. I lived in an abandoned house for a couple nights, and there were lots of caves with long term resident climbers living in them too.
If you go make sure you venture out onto the El Camino Del Rey at least once, if the local gov't hasn't tried to prevent access. If they have climbers no doubt have found a way around it. Pretty exciting and potentially dangerous, but fun....some climbing sectors start from the camino, but by then your roped up anyway! Maybe not a suitable activity for your son, but that is up to you.