Canadian teaching courses in US on contract

Hi. Have searched on what I think is pretty straightforward, but do not see answers.
I am a Canadian living in Canada. A large US firm, is prepared to hire me, through a 3rd party contracting company, as an independent sub contractor to teach sales courses and sales effectiveness in the US, on a very part time basis. I would travel to the work when required.
I have univ degrees and many years experience in the field (as an employee of the client, before I retired).
I have 2 questions.
1. What visa, if any, do I need to do this? Seems a TN is most appropriate, but I am not 100% sure.
2. Are there advantages to having my company contract for this work, or should I act as an individual contractor. I have an incorprated company in Canada now.
Thanks, Mark