Just get a multiple entry tourist visa and plan for some weekend trips elsewhere, since you'll be leaving every 60 days unless you want to extend it to 90 days per arrival.
The 3 months is the recommendation because most other visas have a 3 month validity.
The application form is the same for all the visas, and the only thing that changes is the options for some of the dropdowns. The recommendation stays the same.
But I repeat.
You have the entire duration of your DTV Visa ( 5 years ) to enter Thailand for the first time.
Download the MyAIS app and you should be able to get whatever on-top package you want.
Still sporting the same number I got from the airport in 2021. My main package changed to a mao mao pre paid which costs me nothing itself, and I only pay for the on-top unlimited package.