Would love to do that itinerary - you may find you want to stay longer on Lanta though - it is addictive there!! We stayed 12 nights last year during low season and left completely chilled...loved it!!

We were in Vietnam the year before and loved Hanoi (stayed in the old quarter in a very small hotel called the Classic. Basic but comfortable), Halong Bay (we did the overnight stay on Catba Island in a hotel called the Sunflower - agin basic but comfortable), Hue and Danang. We visited Hoi An on a day trip from Danang, but actually stayed on China Beach in Danag for 4 nights. Not a lot there for tourists but would go back nonetheless.

Have fun

Robyn