Is that £2k within your budget? I always book hotels direct and found that most don't include any food beyond a breakfast.I also had a look at holidays in Komodo national park, and ended up being directed to some general holidays in Bali, the cheapest being about 2k for 2 people, but I didn't check if that included us being fed.
I'd liken Vietnam to what Thailand was probably like before the mass western encroachment and development 30 odd years ago - there are plenty of westernised resorts however and you could do as authentic or comfortable as you like, depending which way your gf leans.Regarding Vietnam, is it fairly westernised outside the capital? My only experience of the east is 3 weeks in Cambodia 4 years ago, which I really enjoyed, but it's a developing country and I know that my GF wouldn't have liked it there.