I love the Italian form: Letizia. Beautiful!I'm in love with Laetitia, and the pronunciation I use is the one you and the OP are using. Totally not a fan of the 'tish' sound. :/
Yeah I would suggest Letizia if you really wanted to avoid it. Laetitia's interesting and very stately, and I like it a lot. Letitia is close to making my shortlist a lot, but I don't mind "teesh" at all and say it that way.