Not knowing much about how you plan to market & sell these products makes it difficult to make recommendations. Also not knowing the nature of the Health Dept regulations may limit what & how you can sell it. In the USA, Health Dept reguations in different areas limit what you can do. For example, in some areas here you must use canned chili, other places you can make your own, etc.
Reading all the above comments, we are assuming there is a market for US Hot Dogs in the UK. Can you answer that question without having sold any US Dogs? You may find your countrymen may not like the tastes of American Dogs. There are some fine sausages available in the UK. Your customers might find US Dogs inferior.
Give us some more specifics about how you intend to run your business. Are you using a cart or a brick & morter building? Are you selling other products? Are their other vendors selling non-US weiners over there now? Etc, Etc