Both would be very easy to grow. In googling, it seemed like Paph. Macabre Contrasts was more likely to have darker colors. Some Paph. Memoria Barbara Duncan turned out less black. These are seed raised hybrids and will have genetic variety.
If you really like black orchids, check this one out: http://www.orchidboard.com/community...l-fcc-aos.html
I'd like to get one of these sometime, they get big and blooming sized ones are expensive. Some people don't like them because they have dormancy and then don't grow or bloom for a few months, I love deciduous orchids for some reason. Besides, they grow extra fast when they do grow and if you damage a leaf, it'll get new leaves next year!