You can directly buy natural black color wigs as follows:

Full lace 130% density, 16 inches to 30 inches available

Full lace 180% density, 12 inches to 30 inches available

Front Lace 13″x4″,  130% hair density, 12inches to 30 inches available

Front Lace 14″x4″, 180% hair density, 16 inches to 30 inches available