Business in the US

Hope someone can at least point me in the right direction here.

I think we could structure the business so that legally the US citizen owned the business and I was an employee (and then would qualify as TN1 still) - but would be interested in hearing of any other possibilities.
Help!

I think an E-visa is the usual way to go.

I would question the approach you propose--pretending to be an employee when you actually are a co-owner. I would think not only immigration but also the IRS would have an issue with that--but the latter is your area of expertise, not mine.

A company in which you have a controlling interest cannot sponsor your TN. Period.