All United mainline flights have Economy Plus seating.

For seating questions, you might want to familiarize yourself with the various seating charts available on:

www.seatguru.com

www.seatexpert.com

International Business Class (even in the current, rather than newer, configuration) is FAR more comfortable than Economy Plus. There's no comparison. Wider seat, more recline, more legroom, legrests, etc. (Some of that will be obvious if you study the seating charts, as well as some of the seating-oriented threads on this forum.)