Here are my personal takes on the names you chose; in the end it's what you like along with taking into consideration that your future child will carry this name for the rest of his/her life (unless he/she decides to change it):
Phoenix - River Phoenix immediately comes to mind although I've known about the Phoenix rising from its ashes prior to ever hearing about RP. I think it's become quite popular, too. I actually know 4 children (all boys) named Phoenix and 2 of them are classmates!
Theo - I like this one, too. I haven't heard that one as much.
Allistair - Our 1/2 British neighbor named his son Allistair - Allistair (or Alli as close friends/family call him) LOVES his name - it's unique and frankly, all his teenage gal pals love his name, too.
Jordan - I'm not fond of Jordan as it's become one of those unisex names that I personally don't like.
Chelsea - My closest friend name her first dog Chelsea so that ALWAYS comes to mind no matter what. She was a very yippy dog. LOL
Kate -
Katie -...I have an unfortunate history of either being the woman that followed a "Kate" or was prior to a "Katie" in 3 relationships so it's on my list of
![Tape](https://pics3.city-data.com/forum/images/smilies/tape.gif)
I do love the name Katherine though (although spelled with a "C").
Chanel - I think it's a bit contrived. Chanel is synonymous IMHO with the brand. I agree with someone that it would be like naming your child after Bentley or Vuitton.
Pilar - I really like Pilar - people really think it's pronounced like "pillar"? I know that's what it means in Spanish but that just doesn't come to mind. To me, it's just a beautiful Spanish name.
Fallon - Fallon from Dynasty comes to mind (Pamela Sue Martin).
Phoenix - Not crazy about the name overall & definitely not for a girl.
As for the other suggestions, I like Chantelle as well but I know that's become popular as well. I think Sophie/Sofia are beautiful but it seems to have become the "Sue" and "Patty" of the last several years.
Mercedes is a fairly popular Spanish name that has nothing to do with the car. It's a reference to Our Lady of Mercy. I've known many people with that name or Merceditas (diminutive). I really like the name Tristan (that's my brother's & SIL's 1st pick for their future son) as long as you can get past the meaning (sad - triste).
Picking names was one of the hardest things for us. We found out their sexes before hand but because we didn't know right away if we were having 2 boys or 2 girls or boy/girl, we had 2 sets of names for each sex and then a boy/girl set (which was basically our favorites from the first 2 sets).
Overall, I really like your picks of Theo (Theodore?), Allistair and Pilar. They are beautiful, less common names and would transition well from childhood to adulthood.