Seth - Pleasant but would keep it as a middle name if at all.
Nehemiah - I really like this said Nechemya, the Hebrew way, but Nehemiah is nice too. Have you considered Noam? Only two syllables and a bit softer? Naphtali seems soft too but is just as uncommon so I don't know that it's any better.
Zechariah - I prefer Zacharias because I like Zach. I also like Zebulon, ("exalted") but most people don't like Zeb as a NN as much as I do.
Boaz - Prefer Baruch or Barak or Benjamin or Benaiah.
Nathaniel - Beautiful. And a little "easier" than Nehemya/Nehemiah.
Jeriah - Prefer Jedidiah to Jeremiah and variants because I like Jed more than Jerry.
Thank you everyone for your thoughts and suggestions. I know names can be personal and we don't always agree on what sounds the best. I think I liked too many this time and kept trying to make lots fit. However, I wasn't the only one to consider. We finally filed the birth certificate....He is officially Nehemiah Seth. I just couldn't get any of the other names to work for him....now if I could just get used to saying it and stop calling him by one of the other kids...sigh..mom of many....