What are the best options for obtaining a work permit on a Non-O visa for future Thai citizenship?

To begin with you first need a job in order to get a work permit. On the road to citizenship, if not married to a Thai, you first must apply for, and get permanent residency. This requires an income of at least bt80,000 a month, but special branch wants to see bt100,000+ wages a month, continuous for at least three years, plus other requirements, that mean nothing if you don't work, and pay your Thai income taxes every year. After you've been on PR, still working, for 8 more years, and paying your income taxes every year, plus other requirements, you can apply for citizenship. If you are married to a Thai the minimum monthly wage requirement drops to bt40,000+ a month, and after three years of working, and filing your taxes, you can apply for PR, or directly for citizenship. The approval fee also drops from bt195,000 to bt95,000 when married to a Thai. The bt7200 application fee doesn't change. The expert on all aspects of this is The Thai Citizenship Group. This is not a process you can use an agent for. In fact the special branch looks down on that.

Why work.

why work

A job offer without sponsorship for a work permit isn't any job offer at all. Move on and continue looking.