Eliana is not my style, but those types of "liquid names" are definitely very on-trend.
I pronounce it EL-E-AH-NAH. The name Brooke is nice and it's not bad as a middle name, but I think some of the other suggestions like Eliana Mae and Eliana Paige work better.
I pronounce it ell-ee-AH-nah. And while I'm a bit biased because I love the name, I really like Eliana and Amelie as twins.