American Relocating Back to the US From Canada

I’m an American currently living in Canada but planning to relocate back to the US within the next 2 years. I am currently a consultant (contracted CFO/COO work for companies that do not require a full-time CFO) in Canada with a few Canadian clients and 1 US client. In my pipeline I have a number of US clients that are interested in my services. I would also like to start a real estate investment business to generate passive income.

The consulting business is already generating >$100K/year billed from the Canadian sole proprietorship.

Given the relocation back to the US within the next 2 years, what is the best way to structure the businesses from all aspects (tax, legal, asset protection and retirement planning). Should I/can I also set up a solo 401(k) in advance of moving back to the US? I and my spouse plan on retiring to the US once we have relocated back.

Thanks,

Scott