Hotels and alternatives
Matmata is the place to stay the night, and you should aim for one of the hotels where you can spend the night in a real troglodyte. Sidi Driss is the location of the Star Wars movies, but Marhala is a much friendlier place.
One thing is to visit troglodytes during the day, another thing is to sleep in one, and wake up in it. The standard is basic, but no worse than what most Tunisia explorers easily could accept. The shared baths and toilets might be the biggest problem for some.
Matmata has a handful of more expensive options too. While these are good hotels, they are devoid of the natural charm of the ones mentioned above.
Restaurants and alternatives
You eat your food in one of the hotels. In this case, going to the good hotels is the better choice. The reason is that the troglodyte hotels are basic in their cooking too. Not bad or unhealthy, just unexciting.
In the better hotels, you will find bars. Some of these hotels will arrange shows, but not every night.
The better hotels will change money, but they are not obliged to do this for non-residents. If you should find yourself stranded without Tunisian dinars, some friendly convincing will make the receptionist help you out. Early afternoon is the quiet part of the day, and also the time when they have best chances of giving such extra service.
Basic buses run between Matmata and Gabes. These are crampy and can be very uncomfortable in the middle of the day when the sun is hot. There are some shared taxis, but not many, doing the same stretch.
There are plenty of 4-wheel drives with tour groups running through Matmata, but they will often be full. Which is just as good: the people inside these cars always appear to suffer from little space and inhuman itineraries lasting from early morning till evening.
Summer is very, very hot in Matmata.
If you're not going with a tour group, try to explore Matmata in the early morning hours. Then the village is almost empty from other travellers and the morning sun light gives the troglodytes a dramatic appearance, which is lost through most of the day.