If you are not certain if you would be able to apply for a K-1 Visa , speak to an attorney to view your chances. If you are self employed or active military member – the requirements for a k1 visa are lower for military members and self employed individuals may apply for a K1 Visa based on the amount of assets you own. This of course can be used to meet the minimum requirements fo the K-1 Visa if you are employed.
If you are thinking of applying for a tourist visa to the US for your Thai girlfriend while in Pattaya in order to get married in the US then take good advice and don’t. This is viewed by the US State department as immigration fraud and this would make for a very difficult situation when she tries to apply for a fiancee visa later. Also apply for the correct US visa and if you plan on taking your Thai girlfriend back to the US to get married then the K1 Visa application in Pattaya would be the best start.