There are a bunch in the Hoi An / Da Nang area. Top of the line is probably the Four Seasons Hoi An, though it is $$$$. The Intercontinental is closer to Da Nang I think and $$$.
There are also probably some independent or regional hotels that will give you much better value, but not quite as nice.

I really loved Hoi An (and the FS).

Doing this will likely involve a flight from SGN to DAD, but it should be pretty cheap and easy.