All sunflowers that are "red" or "black" are actually "burgundy" or "rust." The terms "red" and "black" are marketing ploys, like many "blue" flowers which are really purple.
That said, several years ago I grew "Moulin Rouge" which is a deep burgudy with small splashes of saffron.
Here is an old picture. As you can see, the bloom is the same size of a Tithonia (the bright fire orange on the left), which is to say about 3-4" at most. Edit: just realized the perspective here is weird. The bloom really is the same size as the Tithonia. In fact, some of my Tithonias were bigger than my sunflowers.
The plant is a hybrid so it does not produce pollen or seeds. It branches out in several directions so you could keep it relatively short if you wanted to by pinching it. But be aware that sunflowers often have wider root systems than they're "supposed" to (depending on conditions of light, water, food, etc.) so they can be difficult to grow in containers--even the "container friendly" varieties. They grow VERY fast and sometimes they'll be fine then the next day toppled over.
One other other thing to keep in mind: just because a sunflower is short does not mean it has small flowers, and just because it is tall does not mean it has large flowers. There are examples in both directions that defy what you'd think at first!