Miss Huff may produce some berries, but they will not be viable. This hybrid needs to be reproduced by cuttings.

Though partially dependant upon growing conditions, but you should expect a spread of (at least) 4 feet.

So, would I have to dead head a Miss Huff if it did produce berries in order to keep it producing the most amount of blooms possibel?

Don't dead-head your plants.
Miss Huff produces very few berries, and a staggering amount of blooms.

Here is a link that might be useful: lantana