For the girls, we've got:
Troian [prn Troy-in] - This feels more masculine to me, it's probably the Troy bit that makes me think masculine. I also don't think the spelling is very intuitive of the pronunciation, I'm more inclined to say Troy-an rather than Troy-in, which could be a problem for teachers.
Flannery - Again, this one is more masculine for me. It's nice but it makes me think of flannels, so it's not my favourite.
Gwendolen - I love this one, however I much prefer the Gwendolyn spelling. Gwendolen Pepper would be a very spunky combo!
Pepper (strictly middle spot) - Love this one too, very spunky and sassy. I think the right person can pull it off as a first name, but it does work better as a middle name.
And for the boys, a much longer list;
Hudson - This is growing on me, but it's not my favourite.
Kellan - I like this one, it's similar sounding to Kieran and Cullen, but it's a bit more unique.
Ferguson - I'd prefer just Fergus, although I'm not a huge fan of it. Ferguson reminds me of football players for some reason (football as in soccer).
Gavin - Not a fan of Gavin, tbh I don't understand it's appeal.
Oleander - I'd prefer Leander, the O at the front makes it look unappealing to me.
Benson - Not a fan, sorry. The nickname Ben is cute though.
Tomlin {to honor my dad} - I like how it's honoring your dad, but honestly it just looks made up to me; I'd much, much prefer Thomas or just Tom.
Aslan (stricly middle) {an ode to Narnia, as well as I just think it's a great name} - I can't see it on a baby tbh, but it would be okay as a middle name.
Cillian / Killian [prn Kil-yan] - Love this name, so handsome.
Salem (only in the middle) - I think this is mysterious and handsome. It has the same feel as Pepper to me, spunky and sassy but for boys lol.
Prosper (middle spot, I'm thinking Gavin Prosper?) - Love Prosper, but not with Gavin. Cillian Prosper would be handsome, or Kellan Prosper.
Cabhan [prn cav-in] (probably best to keep it middle spot to avoid pronunciation issues) - I like the look but not the sound, it's just like Gavin for me, except with a C at the beginning.
I feel like I've been so negative, but I wanted to give you my honest opinions. My favourites are Gwendolen and Pepper, and Kellan, Killian, Salem, and Prosper. Did you want combo suggestions?