Depends on location, bank and branch. I opened one in 2021 in Pattaya, Bangkok Bank on 2d Road. Needed a Thai to vouch for me, and a Letter of Residency from Thai Immigration in Jomtien. Just used my hotel address as residence. Was on Tourist Visa.
To my knowledge, there are not any 6 months tourist visas to Thailand. (But many seem to stay in Thailand forever). You can do a 60 days Tourist eVisa and get a standard 30 days extension while in Thailand. That will get you 90 days.
Correction: There is a STV. Which is for 90 days. And extendable twice, for a total off 270 days. (See below discussion).
From there, you will have to look at further options such as education visas or volunteer visas. And of course the old visas hop to Cambodia, Vietnam, Philippines.... which will get you another 30 days, if done by air. Thailand is getting more stringent on these last options.
If you are over 50, you can jump through the hoops, for a retirement visa.
Go online, if available, and apply for 60 day, single entry, tourist visa. No insurance requirements, I am aware of. Second process, is applying for Thailand Pass, will need insurance, that states for COVID, for full 60 days @ $20,000. Just got approved today. Using my standard travel insurance, and letter from insurance company.
Thailand Pass and Visas are 2 different things. Thai Pass only requires $20,000, specifically states COVID. I just got mine approved using Allianz Travel Insurance. Standard Tourist Visa no insurance requirements. I've done 60 days a couple of times.
I've done 60 day tourist visas, no $100,000 insurance requirements. Only, insurance visa requirements I'm aware of is a Retirement Visa, applied for outside of Thailand.