For as often as I fly (which is all the time, I am waiting in the airport now for a flight) I am the BIGGEST claustrophobic there is, I swear!! I do my best to avoid flights that use MD-80 aircraft.(Which is kind of tough on Alaska, but they are phasing them out) They have very short ceilings which add to my issues (although Valium works wonders).
When I have flown overseas, I have flown in 747's in business or first class which allows me plenty of room. I will also do my best to find flights on the big aircraft with very few stops or non-stops. I have been very comfortable flying British Airways to England and Qantas to Australia. Any other flights once I get to my destinations, I just look for flights using a wide body plane and will stick with first class as often as I can.
I will also go look on the Seat Guru to see what the seat configuration looks like before actually booking the flight. A lot of places will tell you the type of aircraft for the flight so you can check it out and pick the seat best for you.
Between that and the Valium all should be well