The 3 major Thai carriers are AIS, dtac and True. You can easily see their prepaid plan options on their websites. All are similar prices and coverage in the major cities.
I hope you can see from my other comments in this thread that the Emirates free insurance coverage IS accepted for COE by many consulates. I provided proof from posts from people who specifically say they used it in the Thai consulates for the UK, Dubai, Portugal and Hong Kong. There are others as well but I don't have time to look them up. Please note that after buying the ticket, you must email a copy of your e-ticket to
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to request your personalized policy document which is what you submit to the consulate as your proof of insurance. The policy covers the exact dates of your roundtrip ticket (up to 1 year) so of course, the policy period must match the requirements for your particular visa's stay. Also, I have written proof from AIG that confirms that the policy DOES cover asymptomatic hospitalization, unlike most insurance policies, which means if you are required to be hospitalized due to Thai regulations if you test positive during quarantine but do not have symptoms, the policy WILL cover your hospital costs unlike most insurers who deny it for not being medically necessary. I posted the proof as comments on another comment in this thread. Also, one tip is to highlight the line near the bottom of the policy that specifically mentions that it covers for COVID. Some consulates don't see that and initially reject the policy but once it is pointed out them, I have not heard cases of it being denied.