If I like these names....

[Silver45]

.... What else might I like? Girl sienna and boy George. Can't use either though as nieces and nephews have these names!!!

Any more to go on? George is a classic name to me so edward, William, James, charlie.

Savannah?

Love savannah- but would she get called savvy?!
Any more?

Names that seem similar in vibe to Sienna:
Scarlett
Ruby
Roxy (Roxanne)
Summer
Autumn
Brooke
Bronte
Darcey

Boys:
Lorcan
Logan
Henry
Leo
Thomas
Simon
Peter
Matt(hew)

Savannah has always been on my list- I don't personally nn very often but you'd probably end up with the odd Sav here and there - i say this because I have a Scarlett and though she's often known as Star, occasionally Scar or Scarly slip out. it's no biggy though and you probably get it with most names anyway.

my suggestions:
Roselyn
Tamara
Josie
Clara
Scarlett
Violet

Frederick
Archibald
Alexander
Daniel
Tobias

Saffron

Peter

Savannah is nice!
I also once knew someone called Sapphire when I was younger and I loved it!

Girls;
Samia
Eva
Ava
Melody
Summer

Boys;
I like George too but spelt the Spanish way Jorge.
Freddie (was my top favourite for ages but my partner just won't agree!)
Oliver
Theo
Frankie

Good luck!

All interesting. Boys names never inspire me as much as girls. Love Ava but wouldn't use as know too many x