Inquiry Submission By McNeil T

I am flying into siem reap, then vietnam, and then flying back into sihanoukville. Only too late did I find out this complicates the cambodian visa situation. Is it possible to get a multi-entry visa on arrival when I land in siem reap? Or is the best plan to just get a new visa-on-arrival each time I land in Cambodia? Are either of these options possible? Is there any reason to get an e-visa(s)?