So you can - and can't - get a Tourist visa at Savannaket.
As for the online system, it's apparently not that easy at all - for some people.
My buddy has been trying for a couple weeks now with no luck. He thinks he's been "blocked" or something, though I suspect it's a password issue.
But even before that, he said he filled everything out, uploaded all the photos/scans (etc etc) and the last step was to pay for it but it wouldn't open the payment page for some reason.
He tried contacting (someone) and somehow ended up with a "password reset" or something.
He's given up and will go the "Visa Exempt/Extension" routine.
However, someone told him he could only do that once and then he'd have to fly out, return, get a new Exemption stamp, then do another exemption.
But it sounds like (in this thread) he should be able to just do a regular border run after the 30 day extension ? No need to "fly out" and back ?