I would have said Elliot but due to your spelling choice it has to be Oliver. It's not really fair to the child to chose your own spelling over the usual spelling as he'll be forever correcting people and lots will just ignore and spell it, Elliot.
Both Olivia and Emilia are fine. Ds1 is 12 and had 2 Amelias and 1 Emelia in his class at juniors. Ds2 is 10 and has an Emelia and an Emilia in his class. Olivia was very popular when ds1&2 were babies/toddlers but I think less so I recent years. I really dislike Paige though and think it jars with your other choices so I'd have to opt for, Olivia Grace.
Can I ask why you've chosen to spell Eliott in that way? Would you consider Eliot if you don't like Elliott? Notice when you type them here the way you've spelled it comes up as a spelling error; the other two ways don't!
ImperialBlether: I have always loved the name and don't mind any of the spellings, but my brother passed away when he was 10, from a brain tumor, and the fact that the name is normally spelt so wrong, I wanted to use Eliott - the way in which his name was spelt
I have found out that it's a little boy, but now have to choose between Oliver or Eliott! I will most likely use James as the middle name, but I known that's so popular, so that's why I was debating Craig or Blake, especially for Oliver, as that's SO common!