And don’t take the OA route. Better go the normal O for retirement.
It doesn’t need a health insurance, which you need to exchange after a year anyway into one that really fits your needs and is not from a list of expensive companies.
Plus: you don’t need an agent. The majority has done it without agency. It’s really simple. The agency just does it for you.
Except: if one doesn’t have the money, then they bribe for you and you can’t evade it in the future.
Decide what you want. Then choose a matching visa.
3 months per year is (right now) visa exemption plus extension (60+30 days). Cost: negligible.
9 months: you need a long term visa like nonO (if you qualify, its extensible forever) or DTV (5years) or LTR. It all depends on you (age, wealth, wants, needs).
Detail: staying 180+ days per year makes you a tax resident (in about every country) and you probably don’t want that.