Congrats on your decision :)
I love Theodore. I think it is getting more popular but it's not super common - I only know one. Teddy is cute for a little kid but Theo is a good back-up nickname for when he's older.
Abraham sounds very Biblical and also very dated - I think of Grandpa Simpson unfortunately!
Daphne is nice but Hilda is too dated for me.
Some suggestions:
Girls
Mabel
Norah
Edith "Edie"
Evelyn
Heidi
Teresa
Olive
Pearl
Boys
Frederick
Harvey
Gregory
Peter