Where is your business heading?
As a business owner, you are a wealth creator. Because the business is very successful, then its value is likely to dominate all of your other assets. This is risky. Is it better to spread that risk by finding an equity partner?
So how can you finance the expansion of your business?
And how capable is your board of managing the necessary growth?
You came up with the original business idea but you may not be the right person to take the business to its next stage of development. This is not just about management succession, because if outsiders are going to join your company, then its culture may not survive this change.
I think that it well help if I take a detailed look at your operations and prepare a report for you on the choices available to you.