Please help me. I have questions on Japan Visa, Certificate of Authenticity and the best pathway in securing a SIT / TESOL job.

1. SIT or SCHOOL TESOL- I'm considering taking the SIT certification - the SIT school said they might not teach the SIT but instead just teach their own tesl certification because of a limited number of applicants. If that's the case I can take the certification from any school - and I was thinking of Thailand then applying for jobs in Japan. Which way in getting a tesol certification is best recommended in getting a Working Visa in Japan ?

2. BEST TRACK IN BEING LEGAL: After I get certified I want to go to Japan and teach. I have family in Japan I can stay with after the course is done. I was thinking of going there first as a sponsored relative of a family national, but I won't have a working visa yet. In fact I would like to apply for a working visa in the States before going but I think I need to already have a job secured to apply for a working visa. How should I fill out the Certificate of Authenticity and Visa form so I can convert it to a working visa later and avert any complications?

3. WORKING VISA:

I have family who can sponsor me as a national relative but not as a company - but I can work under that?

Please advise - in fact I want to go to Japanese language school for the 1st month then find work
... So how can I go about this job search after I get there?

I hear that it takes 2 months to get a working visa, so... Do I need to find a job pretty fast to sponsor me ()in the 1st month on a visiting visa?.
Or can I apply for a working visa without sponsorship and submit the application before I enter Japan?

4. Oh and the new Japan gov. law: How can I qualify for health insurance under the new health insurance law requirement if I'm searching for a job while there?

Thank you, Elise