It seams that other species are not suitable. There are many types of tea, because of the various conditions in which the tea-plant grows, and because of the various methods for preparing the leaves. To make black tea, which is called red tea in Asia, the leaves are fermented for several hours before being dried. Green tea is made from unfermented leaves, and Oolong tea is made from partially fermented leaves. The species C. japonica and C. sasanqua are not usable for tea, but oil is collected from the seeds, which is used in cooking and the production of cosmetics.
Camellia oil is used in shampoos and creams to moisturize hair and skin.
I enjoy taking pictures of beautiful flowers, but I am not a gardener. If you have questions about growing camellias, it would be best to ask someone else. However I'll briefly describe the necessary growing conditions. Camellias can be grown from cuttings. The cold tolerance depends on the species, but generally, they can survive up to -10 degrees Celsius.