On a recent trip, I came across a Hebrew-English Sepharadi Tisha b'Av siddur (after years of searching). It's Siddur Kol Eliyahu published by Congregation Shaare Rahamim in Brooklyn, NY by Rabbi Shlomo Churba. To purchase copies, I imagine that you would call Congregation Shaare Rahamim at 718-951-6226.) The credits page says that the kinot translations (which are approximately the only thing translated in the siddur) are used with permission from Siddur L'Tisha B'Av published by B'nei Shaare Zion (also in Brooklyn, a quick Google search tells me their number is (718) 376-0009), so there may potentially be two extant Hebrew-English Sepharadi Tisha b'Av siddurim in the world.

One big caveat of Tisha b'Av siddurim is that every siddur seems to be very different from every other siddur. Though they share many kinot in common, they also have many different kinot. Siddur Kol Eliyahu is according to the syrian minhag, and it's different from Avodat HaShem and Or Vaderech (which are, in turn, different from each other.)

But if you're Hebrew isn't good, and you're looking to find more meaning on Tisha B'Av (if chas v'shalom the mashiach doesn't come before then), then these might be worth looking at.