While it can be done, there are other far more economical planes that can fly the long, thin routes. It really makes no sense to do it with an A300-600 unless you only need a couple and you don't want to take the commonality hit by going with a different model or you already have one on-hand and you want to fly the route while waiting for a more efficient option to be delivered.
The A310-300 is the most obvious choice but may not be available yet in your game.
The 767-200ER or 767-300 can carry more passengers (far more with the -300) further while burning a good 10% less fuel
The DC-10/L1011 will use more fuel on the route but can carry far more passengers. While this may be inefficient right now, remember that route demand grows, so the demand may grow into their capacity in due time.