Availablity of the Works of San Juan de la Cruz
First, many thanks to Mr. González for the advice on Spanish Versions of San Juan's works.
Now, a response to the query he posited--what are considered the very best English translations of San Juan's works can be found at ICS publications site. Go to the Archives and you'll find on-line English translations of everything except Ascent of Mount Carmel. The somewhat stodgier, older translation of Ascent by E. Allison Peers is available here. The Kiernan Kavanaugh/Ottilio Rodriguez translations available at ICS are considered among the finest. Also, they did tremendous editorial work that resulted in a much expanded version of The Sayings of Light and Love. Enjoy!