I am usally a United flyer, so this will be my 1st time on EVA or China Air

I will be flying from SFO or LAX to TPE (departing Fri 8/1 in the late afternoon)

Which is better EVA vs China (fly Economy)??

On EVA how does one get a Premium Economy Seat? What is the fare basis for them? Does a 'B' fare get into Premium Economy.

Any help/tips would be great

Thanks