H1B vs J-1 visa

I have been offered a position and I always thought the only visa i could apply for was an H1B (my job is not on the NAFTA list). Now an immigration attorney with this company is suggesting I come down on a J-1 visa (under the "teacher" category) and then if I like it, apply for an H1B later (just to clarify I am not a recent grad, i have 18 years experience in a specialty field). i think I can go down on J-1 for up to three years. Her reasoning is that it is cheaper but what are potential pitfalls of doing this? I'm thinking taxation for one. There is a 2-year residency requirement so I would not be able to switch my tax base to the US for 2 years. Am I getting this right? Are there any other pitfalls?

You can move your tax home whenever you want, J-1 has a tax advantage on the US tax side as it's FICA-exempt but it's not really a tax advantage in reality because to qualify for it you must still pay taxes in Canada, so what happens is that you pay less in the US and more in Canada so it's academic usually. Just means you have a smaller foreign tax credit. Have a read of IRS publication 519.

Teachers can also go in as TN-1 for institutes of higher learning. If you're a teacher at a college (post grade 12), H-1Bs for that are quota exempt.

Thanks Steven, it's with an elementary school so no, it's not TN eligible (it's as a speech therapist but we are considered "teachers" in the US). I saw that J visas are exempt from FICA but as you say, it's hardly worth it tax wise - I'll just end up paying a lot more in Canada. I guess the H1B is really the better route. I just wanted to make sure I wasn't missing some "advantage" to a J-1 that I was unaware of.