I love Beatrice and the nickname Bea (pronounced like bee). I say it BEE-uh-triss, not BEE-TRISS which I believe is the more British pronunciation. I just think the spelling is so beautiful and the sound is very classic.
The x and z of the other options are a teensy bit trendy, though they are obviously legitimate names. With Beatriz, I automatically say it as beh-ah-treez because that is the more latinate version and I am used that that being a name for people in Spanish class and such.
The trix ending to Beatrix kind of cheapens that name for me. It's just a personal preference.
With Isabel... I'm not sure I particularly like any of them just because of the repeated B-sounds. I think Beatrice and Isabel would make really great sister names though! Isabel Beatrice is still very pretty, I just have a pet peeve, haha.
Not sure how you'd pronounce Beatriz in English, but I'd only use it if you're of Hispanic heritage. Isabel Beatriz is very Spanish.
Between Isabel Beatrix and Isabel Beatrice, I think I prefer Isabel Beatrice.
I like Beatrice but only with the Italian pronunciation (bay-ah-tree-chay) : )
i think beatrice is the best. the x is a bit much. and beatriz i want to say the spanish pronounciation which i assume is BAY-ah-treese
Isabel is lovely. I think I'd go with Beatrice. Isabel Beatrice seems to fit together best.
HTH Luv Sar xoxo