I am traveling From Cambodia to Thailand to Laos and back to Cambodia.I am wondering about crossings at Koh Kong into Thailand and crossing From Chiag Khong,Thailand into Houei Xai,Laos. If I use the "boarding crossing paper work" that I can order from GT Rider, will that be enough? Or is there more to it?Also,can I get 30 day visa for each country, Thailand and Laos?Have heard only 15 day visa if crossing by land. Any help and advice would be greatly appreciated. Thanks