Opinions wanted on our name list...

Boys:
James is one of the most common middle names (or the most common?) for boys in the UK. Which is why I personally wouldn't go for a top 20 name...

• William: nice but rather popular.

• George: too popular.

• Samuel: nice.

• Charlie: Charles is nice. Charlie is cutesy/nickname-y imo.

• Reece: Rhys would be very nice.

• Jenson: I know a great guy named Jensen. Which is probably why the Jenson spelling seems a bit strange to me...

• Ava: imo very boring.

• Ayda: not my cup of tea.

• Alissa: it's ok.

• Annie: I prefer Anne/a nn Annie.

• Emilia: very nice.

• Eva: popular but classic. It's really nice imo.

• Edie: Is this short for Edith?

• Darcy: I personally dislike it.

• Ivy: cute.

• Nancy: adorable :)

• Phoebe: lovely.

I like most of your choices actually! My favourites are
William
Samuel
Charlie

Emilia
Eva
Darcy - I would spell Darcie though
Phoebe

I actually really like most of those names !

Because most of the 'old names' are quite popular now I think I'd personally rule out William, Charlie & George as they're quite common. I do love George though I really like Samuel and Jenson, so I'd choose one or those myself. Probably Samuel if I have to pick.

The girls names are all lovely too. I have a Phoebe and I've loved the name forever, so that always gets my vote. I also love Ivy and Ayda (though I'd spell it Ada I think).
Again, Eva/Ava/Emilia are all very common, so I'd rule those out, although all lovely names. Nancy is the only one I'm not really keen on.

So for me ! Samuel/Jenson for a boy, Phoebe/Ada/Ivy for a girl

For a boy

Samuel James

Or Rhys James but only this spelling

For a girl Phoebe Emilia or Annie but not sure any of your choices really work as a middle name due to similar endings