A good start (which will give you some characters) would be to read Max Hastings' 'An Epic Tragedy.' It is quite a tome, but very very readable. The first part deals with the French in Indo-China, and the account of Dien Ben Phu reads like a Greek tragedy unfolding.
I've often thought about wargaming the Vietnam War, as from a political, strategic and tactical level it is a fascinating conflict. But I've always felt uneasy for personal reasons. A (much) older cousin of mine was with the Kiwis serving with the ANZAC contingent there. He had aspirations as a regular, of a career as an officer. It really screwed up his life, and like a lot of Kiwis and Aussies that were regulars, after the ANZAC withdrawal, he went on to serve in the 70s as a mercenary in Rhodesia's bush wars, and then became another junkie beach bum of a type that were so common in Bondi in Sydney the early 80s.