I'm not a big fan of the name in general, but if I had to pick, I'd definitely say
Isabel. It looks slightly more sophisticated and a bit less trendy. I do adore nn
Bella! I think
Isabel Aurora is actually quite pretty.
Lilly, I only love as a nn for
Lillian.
Madeleine is ok and the names go together fine, but they're not "wow," in my opinion.
You do seem to like fairly classic names, and I generally do too, so I'll give a few mn suggestions for
Isabel.
Isabel RuthIsabel ElaineIsabel JuneIsabel VioletIsabel MaeveIsabel HesterIsabel Sofia (similar to
Isabella Sophia, but I like it ever so much better)
Isabel AriaIsabel CatarinaIsabel CatrinIsabel ClareIsabel FelicityIsabel HopeIsabel HonorIsabel JosephineIsabel KateIsabel LavenderIsabel LouisaIsabel Mercy