I will be flying IAD-NRT-TPE in a few weeks, and am somewhat of a United novice. My ticket is full-fare coach, but on such a long flight, I'd prefer to be in business class. (And I'm surprised to find that Economy Plus is not complimentary! Amazing.)

Anyway, what kinds of options do I have? Are there complimentary space available upgrades? I have over 200k US Airways miles, and I wouldn't mind using some of them if necessary.

Thanks in advance!