if you are a professional, only choice is to find a MNC posting in Thailand. Else will not be easy to land into other jobs due to work permit restrictions.
(Edited with additional info) there are few factors to determine type of visa which suit you best, age? nationality? job? if your job allows you to work remotely, then DTV give you for a 5 years visa. Else you have to explore others. just google the thai embassy or consulate webpage at your residence country, all the visa types and requirements are listed there
180 days count is the last day you need to exit Thailand, you can return on day 181 and restart your next 180 days stay. Or anytime within 180 days you depart, and new 180 days reset on your return.