If you want to save money. Go to their eastern terminal (ekkamai) and ask for public transport. They use those public van. It's not so comfy but way cheaper.
Then you should go to Thai Embassy nearest to you and request for one. Nobody here in fb is able to give you a visa to enter Thailand legally, not even Mark Zuckerberg.
Business visa and work permit are two separate things, issued by two separate government bodies... but you need both to be legally working in Thailand. It's best to consult an expert on this matter rather than asking it in here.