I slightly prefer Julia but I always think Julie looks and sounds very cheerful somehow. It's not common nowadays, but remember children of the same age don't know that, and it's certainly not a "weird" name that anyone would make fun of. I say go for it if you love it. Having said that, Sarah is one of my all-time favourites! I quite like Aisling, but unless you live in Ireland, I think it will be mispronounced a lot.