Yes, now that I've met Journey to the West, it seems to be lurking in the background of every manga I've ever read and every anime I've ever watched. :-) Which of course makes sense, if all the folks who wrote and drew them grew up on this story!

There are apparently only 2 (or 3, depending how we count) unabridged translations into English so far. I'd bet that your digital copy is of either Anthony Yu's original (4 volumes, 1977-83; with extensive scholarly introduction and notes) or William Jenner's (4 volumes, 1982–84; with "no scholarly apparatus," Wikipedia says).

The one that I'm reading is Yu's updated 2012 edition of his own earlier work. The update was apparently his "retirement project" at the end of his career; he amended his translations based on newer scholarship, and revised and extended his notes and introduction.

I hope that it turns out to be fun for you! No problem if it doesn't of course. :-D