Everyone has got their own travel tastes and interests, but I would strongly encourage you to look again at Hanoi. The French influence you are seeking is absolutely there--Metropole Hotel, Opera House--as is the shopping: plenty of Uncle Ho/Communist propaganda to buy. As a tourist, there is more to see in Hanoi--Hoan Kiem Lake, Hanoi Hilton (not literally the hotel chain, as their is now one of those in the city), Ho Chi Minh's Mauseleum, the Capital, the French Quarter. Where Hanoi is cultured and romantic, HCMC is recklessly fast and urban. It is certianly a part of the country to see, but I question whether it truly stands on its own as a tourist site. I would also suggest that the attitudes, culture, even archetecture in HCMC are less indictative of what you'll find throughout the country. At least that was my observation.