Multiple friends recommended Vietnam as a destination. I found Evaneos by 'accident' via Aunt Google (as well as 1-2 other companies offering custom private tours via local travel agents). I liked Evaneos best based upon my internet search.
I corresponded with Sen at Absolute Asia Travel over the course of several weeks (and multiple drafts of our itinerary) until it seemed right. Sen was very helpful & patient throughout this.
~15 days there, arriving in Hanoi and departing from Ho Chi Minh City: Street food tours, bicycling, caving, cooking classes, relaxing at the beach, and back of the Vespa rides were just some of the many things we did.