Eliza is beautiful with the siblings! I think you might want to consider a name with an N in it to subtly tie them together. Some options:
I think some of these are better than others, but I think they could all work...
Elliot (although this might make a future Eliza tricky)
Sure there are more. All best!
Wow! Thanks for your suggestions. I didn't want to mention my ideas offhand because I wanted to hear a variety and that, I did!
My favorite boy's name used to be Elliot until I had one in my class (for three years, actually) who left a bad taste in my mouth. It's been awhile, though, and I am coming back to it. Husband isn't sure. I've thought of the nn Leo. This will be our last, so if it's not an Eliza this time, there won't be one.
Milo is another I keep coming back to. I love the long i sound and the long o is nice too.
I also like
Arthur - Too much like Oliver? I fear this with the -er endings.
Henry - Overused?
Lachlan - A guilty pleasure - I love this, but don't think we'd actually use it. I'm from Minnesota and do love my lakes, so it's fitting.
Jonah - Does this make him a Joe? Not a huge fan of that nn.
Theodore -I like the long form better than nns, though. Theo still makes me think of the Cosby show and Ted isn't my fav, though I do like Teddy.
Our dads are John and Michael, so I've also thought of variations of those, but Evan seems overused and I'm just okay on Ian.
Thanks so much for your thoughts. I'd love more!