If it is possible for you to get a trustworthy partner I believe that it is something that will help to grow the partnership business very well but when you cannot it is better for you to run a single man business.It depends entirely on how big the business is or how you plan to expand in the long run
For a small business, a sole proprietor might be a good idea if the person can handle everything that comes with the business.
However, as time goes on, if there is a need for expansion, and the person finds it difficult to take care if the business as a whole, then a partnership could be required for such business