Before considering keeping any species of Corydoras, whether they are common or rare there are a few things to that need to be looked at, and a few questions to be asked.
Firstly and the most important item of consideration is the environment in which they are to be housed. Most Corydoras species will live quite happily in a relatively small aquarium, a single pair of fish in a 25 cm x 20 cm x 20 cm (12' x 8" x 8") tank would do fine, but if you want to give them some company! Say another three or four mates of the same species and a few tetras or Barbs, then larger surroundings would be a must, a tank of 60 cm x 30 cm x 60 cm (24" x 12" x 12") would be a good size to start with.
The equipment and decoration to a certain degree is all a matter of choice, but there are some areas that should be given careful consideration, the main one of these is the substrate that is to be used. My recommendation is the use of fine smooth gravel or a course grained smooth sand, to a maximum depth of 15 millimeters this allows the catfishes to reach through to the base glass of the tank and find all the particles of food that have penetrated deep into the substrate.
I emphasize the smooth because this is extremely important when it comes to keeping Corydoras in the best of health and condition. Any sharp edged sand or gravel can very quickly damage the delicate barbels of these busy little fishes, this damage in turn can lead to bacterial infection and fugal attack which may in turn be fatal.