Visas and border crossings forum

Hey there world travelers,

In just a few days I will be making my way to SEA for a 2 month trip through Vietnam, Laos, and Cambodia. Being that I am flying into HCMC, the Vietnamese visa was easy to figure out. This being said, I've done hours upon hours of forum searching and internet perusing and still the visa info for Laos and Cambodia remains a slight enigma. The reason for this is that I had to go and make things complicated by wanting to cross into Laos by way of the Tay Trang/Sop Hun border with Vietnam and then continue into Cambodia by way of the Veun Kham/Dom Kralor border. Finally, I plan to cross back into Vietnam and return to HCMC for my flight home.

Thus, my questions are about the visa requirements at these border crossings. From numerous sources online, it seems that both the Tay Trang/Sop Hun border crossing and the Veun Kham/Dom Kralor border crossing offer a "visa on arrival" service. This being said, I've also seen numerous posts making comment of the supposed service that previous arrangements must still be made in order for it to actually work. Namely, my question being for both borders and the supposed service is if I were to have the application form filled out, the correct number of passport photos, my passport itself, and the visa fee (including the nicely corrupt "stamping fee"), will I be able to arrive at these border crossings and receive a visa without too much delay or discussion on the matter?

My next question, which also pertains to said borders, is of the inconsistent information about whether the border officials will need "proof of departure" in order to receive my visa. I've seen a number of sites claim that this "proof", whether it is a copy of my itinerary or a bus ticket for my departure from Laos, will be required at the border for one's visa. Now this is where things could get rather annoying for me, seeing as I really won't have an itinerary of any kind and certainly won't have a bus ticket of that kind (I mean I don't even know when I'll be entering or exiting the country). Everything for me is really quite tentative, thus the predicament.

Lastly, I know there is the possibility of getting these visas in Hanoi at the Laos embassy and Cambodia embassy. Any info on this option would be greatly appreciated as well.

So there it is, sorry for the long post guys, hopefully I made everything clear.

Cheers,
Gorgonzola