Visa on arrival over land or flight

Hi there,

I have a few questions. We (a friend and I) want to travel to Hanoi in Vietnam. Having the Dutch nationality we need visa in order to enter Vietnam. We are in Laos now and are in doubt whether we should take a flight or go over land. Is it possible to get a visa on arrival if we go over land? How time does it take to get visa from the day of application?

Thanks a lot in advance!

Kind regards