Increase the quantities of everything equally for more servings - the method is the same, it will just take a little longer to bring the soup to a simmer.
Some versions add the egg more as egg drop - if you prefer this, gently beat the eggs before adding. Stir the soup so it is moving a bit then add the egg and continue to stir so it cooks and separates at the same time. If you choose this method, you will probably need less eggs (even half) but you can judge to taste.
You can use smoky or spicy paprika, as you prefer. Sweet would be fine as well, but the flavor is less distinct so the others add more to the flavor of the dish.
Some versions add some serrano ham into the soup, crisping it slightly with the bread or as a garnish so feel free to add some (or other variations as mentioned above).