Need Help! Series 65, 6, or 7

Hello,

  I am in the health insurance industry (Independent), mostly individual and small group policies. I have basic knowledge of the market (by no means a pro) and have been investing....mostly in mutual funds for the last 12 years.  During many of my insurance sales I come accross clients who ask if I offer other services such as Mutual Funds, Stocks, Retirement Planning, etc.  I am losing additional income by not being able to offer advice or at least sell some of these products on the side.  My question is, should I obtain my series 6, 7 or 65?  Also, any suggestions regarding any broker/dealers that would allow me to operate in this manner, taking into account the sale of these products would not be my primary source of income. Thanks   Danny