I'd pronounce
Talia as TAL-ya and
Thalia as THAY-lee-ə. I prefer
Thalia, because
Talia is the Polish word for waist.
Middle names I think would work with both spellings/pronunciations:
EvangelineEveFelicityGwenHermioneJane
masculine list:
https://www.behindthename.com/pnl/191050/124079feminine list:
https://www.behindthename.com/pnl/191050/124080