Hi again,
Here are a few very brief comments.
customers people who buy, who pay eg The store was full of customers.
consumers people who buy and use a product. The store owner who buys TVs from the factory is a customer of the factory, but he is not a consumer. The people who buy TVs in his store, then take them home and watch them, are consumers. However, the store owner calls them customers. 'Consumer' is a word more often used in govt, and business analysis. eg Canadian consumers are spending more on TVs this year.
clients a more professional kind of word for customers. A restaurant has customers. A lawyer or an accountant has clients to whom he supplies professional services. eg The lawyer was in a meeting with an important client.
Perhaps you'd like to write a few sentences, and I'll tell you if they sound OK.
Best wishes, Clive