Choosing the best structure for your business depends on your plans and priorities- so I can't give you specific input without more information.
However, here are some general comments:
1. The dba is not a business structure. Sounds like what your friend suggested is to operate as a sloe proprietor and secure a dba so you can use your chosen company name
2. While this approach is the simplest, easiest and cheapest to set up and maintain - it offers no protection / separation for your personal assets. You are the business and and will be liable for it's actions. It also limits what you can do about acquiring capital- should you ever need to do so.
3 Both the LLC and Corporation approach create separate "entities" which separate your personal activities & assets from those of the business.
4. The Sub chapter S option creates a pass through taxation entity which means that the corp. doesn't pay taxes on it's earnings but "passes them through" to the owners. There are some restrictions and rules concerning the operation of an corporation under Sub chapter S which should be considered before choosing that option.
5. The LLC offers the separation of activities (like a corporation) and the pass through taxation of an S Corp. It offers more flexibility than a corp but is fairly new and doesn't have the amount of legal precedence as does the corporate structure.
Hope this helps. If you want to discuss your specific situation, please drop me a PM or contact me directly using the address in my signature.
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