I'm afraid I don't know much about the current situation with US-UK flights. Our pet relocator informed me last week that BA was still allowing birds on their flights (not in the cabin) from Singapore, so maybe you could check with them.
About a year ago, Continental was a good choice, but I don't know about their recent procedures. Also, KLM are suppose to be good with animals, but I don't know what their stance is right now with Avian Flu.
As far as the quarantine, the UK allow an in-home quarantine (I believe it's 35 days) provided that the inspector at the airport says they appear to be in good health. The home (quarantine premises) cannot have any other birds in the house or anyone who lives/visits the house who works with (or is around) birds. A DEFRA approved vet will have to check your birds within the first 24-48 hours (can't remember exactly) and again towards the end of the quarantine. They also have the right to inspect your birds at any other time. However, they can change the quarantine procedure at any time, so you have to keep your fingers crossed at all times.
I haven't actually experienced the quarantine on the UK side yet, but that is how it's laid out by DEFRA.
Here are the new EU guidelines for bringing in a pet bird to the UK--of which, you have to fulfill at least one (along with the other documentation and permits). We have decided on the 4th option.
You can bring the birds into the UK if you can fulfil one of the following conditions:
· The bird(s)have undergone a 30 days pre-export isolation at the place of departure in a third country listed in Decision 79/542/EEC, (unofficial consolidated version) or
· The bird(s) have been subjected to a 30 days post-import quarantine in the Member State of destination on premises approved in accordance with Article 3 (4) of Decision 2000/666/EC , or
· The bird(s) have been vaccinated and at least on one occasion revaccinated within the last six months and not later than 60 days prior to dispatch, in accordance with the manufacturer’s instructions against avian influenza using an H5 vaccine approved for the species concerned, or
· The bird(s) have been isolated for at least 10 days prior to export and have been subjected to a test for the detection of H5N1 antigen or genome, as prescribed in Chapter 2.1.14 of the Manual of Diagnostic Tests and Vaccines for Terrestrial Animals carried out on a sample taken not earlier than on the third day of isolation.