Cigna undoughtly..U mentioned your British ,cigna is a British company also based in Thailand, to my own opinion ,based only on my own research and knowledge ,Cigna is the best choice ,beeing around for many years in the region allways at the top 3 in costumers reviews ,have an excellent net of hospitals /doctors/and professionals who they work with ,spreads all over the glob ,most times pays or commit to pay directly with the service suplayers,so you don't have to spend money from your own pockets,and gives answer to the things you've wrote your looking for.
Some countries can enter Thailand without a visa for up to 60 days, and this visa exemption can be used twice in a calendar year when entering via land or sea, but with no limits for air travel.
Tourist visas:
Multiple Entry Tourist Visas (METV) might allow for a 60-day stay per entry within a 6-month validity, with the ability to leave and re-enter to reset the 60-day clock.
ok friend ,although you know it all still I will do the effort to explaine..the rule in Thailand as written is that you can only stay in Thailand on a tourist visa for up to 180 days per culunder year.you can decide them as you wish .this is the rule .you can check it before you dismiss it ,cause its a fact ...
Now ,is Thailand a place where you can "bend"the rules ? Yes , absolutely, asppacialy if you have money .never the less if you do you might get in difficulty once you'll want to make a l.t.v if some sort if the immigration officer who deals with your matter is more strict or just wants to ..in general I advise you to check the facts better before you reply