Never been to Vietnam but certainly wanted to go there when I was relatively close, in the
PR of China. My Chinese friends were horrified (not much love across the border).
At the risk of my stating the already known, I've found Lonely Planet guidebooks to be indispensable for independent travel-- I am sure that most of your questions and curiosities would be answered there-- although on the SEL thing, I highly doubt you'll be able to get something.