It is time to consult with a Certified Public Accountant with experience in international corporate tax matters. Or perhaps a chartered accountant in Canada, in addition to a CPA in the USA.<p>The accountant(s) can save you a lot of money by advising you on appropriate record keeping, business entity structure, appropriate characterization of the transactions you describe, as well as knowledge about tax rules that you may trip over (with associated penalties). Plus hiring one would allow you to spend your time and effort better on the business you know.<p>There are some very significant rules for bringing money into the US, from a tax perspective, with heavy penalties for failing to do so with appropriate tax declarations.<p>Since you are apparently profitable, this should not be a burden to you, and if you're not, yet have significant assets, conducting the tax matters appropriately is a cost you are able to pay to avoid trouble, and avoid needless risk.<p>I'd estimate you can save enough money by being well-advised that it would more than pay for the professional fees by avoiding trouble, and perhaps by taking advantage of appropriate tax rules for your situation that you are unaware of.<p>It is a good accountant's business mission to save people more money than their cost, and aid people to grow their business.<p>Doubtless you have business relations with people who have accountants they trust and rely on. Just like hiring a lawyer, you can talk to an accountant in a hiring conversation to learn of their expertise, interest and compatibility with your desires, without the obligation.<p>There are business associations, such as Chambers of Commerce (since you're in a border state) that may have people who have experience or opinions about people or firms to suggest you might engage.
Work your network.