Does anyone know of a good English translation of Etz Chayim by the Arizal?
You can purchase an English version of the sefer here. It also includes some explanation of difficult passages and a clear introduction introducing the basics of kabbalah.
I am not certain if it contains everything that is in the original Sefer Etz Chayim by Chayim Vital, but it is a good start nonetheless. I have read the book, but I have never read the original ספר עץ חיים so I cannot vouch for its accuracy in that regard.
An English translations page for the Arizal's works has been started at Wikisource. As of Mar. 2021 there is just a little, but if everyone learning contributed a bit at a time (or if someone contributed a lot at once) ...
Sefaria has Chapter names in English, and some sections have summaries or notes as of Mar. 2021: