Just a suggestion with naming a second child... Be sure to say both kids' names together, since you'll probably be using them together a lot! See how they flow when you say "Scarlett and....."
I love the name Scarlett and think it's just different enough. That's what we aimed for. Something that was a little different, unique, but no so far out there that people had trouble pronouncing it. When we named Aidan 13 years ago, it was very uncommon and we loved it! Since then, it's become one of the most popular boys names in America. Guess we were trend setters!
As for nicknames, that's actually what we used with our second son. We loved the name "Eli" and knew that's what we would call him, not Elijah or Elias. So his legal name is Eli. Still haven't heard many of those. But--funny aside--I'm amazed at how many people can't read that name! It never occurred to me at all that anyone would mess that up. But at doctors' offices or anywhere where they're reading his name off a paper, we've had numerous people pronounce it "Ellie" as in a girl's name! Really?????
Some of the girls names we considered were Kyra, Claudia, Gabrielle (Gabby).