Ease of set up, funding, liability, taxes, management and exit strategy

John and Susan have a great idea for a new internet company. They will be selling a new health drink that promises to provide natural protein and vitamins without gaining weight and without having any adverse consequences. They want to set up the most flexible business organization. They do not want to worry about going public yet, which would be down the road. They are concerned about the ease of set up, funding, liability, taxes, management and their exit strategy. What type of business organization should they set up and why? Please comment on the ease of set up, funding, liability, taxes, management and exit strategy. Also, please mention whether the liability issues will always remain the same or is there anything they will have to do initially and on an on-going basis to minimize their liability.