Like Marc, I would not buy an AT-545 equipped bus for that trip.
But..... To be fair, a number of folks here have successfully made cross country trips with 545's.
Take a look at Brokedown's travel thread. Josh pretty much circled the country in a T444e/545 equipped Vista. His new bus is the 5.9/545 and he is happy with it. He is a much more patient man than I am.....
Different strokes for different folks