I think they all go really well with Claire. I'm surprised your husband thinks Eliza seems old, but not Estelle, which to me seems the most vintage of your picks. Of all of them, I think Julia is my favorite, but honestly though, they're all lovely names, and I think that any choice you make choosing between them will be a good one.

Any ideas about middles?

Julia is really pretty. I like Estelle too though - haven't heard it in forever. Julia Marie might flow better than Julia Maria, but it depends on your taste and your last name.

I love Claire and Julia!  I have neighbors names Julia (daughter) and Claire (mother) and I've always thought they sounded more like sisters than mother/daughter.  They are from the UK though, so perhaps they would sound more like mother/daughter there?

I also really like Estelle, though I think Stella might be just slightly a better match for Claire. 

Madeleine is a name I loved a few years ago but where I am there are tons of Madeleines of all spellings plus Madisons and a few just plain Maddies, so the whole name family seems a bit overdone.  I also think it's more likely than Claire or Estelle to eventually sound dated.

If your husband likes "safe" and you like more old fashioned, have you considered just using Elizabeth?  You could call her Eliza as a special nickname (perhaps it'll even catch on with other people) and your husband might be more comfortable with Elizabeth.

Another vote for Julia!

Julia or Madeline. I don't think Estelle matches at all to Claire. Maybe use it in a mn spot.

Do you think you could do Maren as a middle to Julia? Then there would be great callback to the "air" in Claire, and Julia already echoes the "oo-ee-ah" of Louisa. Just a thought, but I love this idea of tying the sisters together with secretly matching names.

Here's another vote for Julia, from a Julia. It's a good name: easy to spell, reasonable nickname options (neither too many nor too few), and timeless (since 1880, it has never ranked higher than 26th or lower than 142nd).

I second the suggestion for Marie as a middle name. The cadence works out better than Maria, plus it'd be a subtle match to Claire in spelling (same a-i-e, with an r that moves over one place), just as Julia and Louisa are a subtle match in sound.

I also vote for Julia. It goes well with Claire and is classic, easy to spell and pronounce and unlikely to be super popular in your circles.

Estelle I like but not with Claire and it does feel more vintage than Claire or the other options. Madeleine I like with that spelling but the number of Madalyn/Maddeline/Maddie variants running around has turned me off the name a bit.

Eliza is a great option and not at all old lady to me. I know a couple of young Eliza's. 

I agree that Julia Marie is a nice combo or Julia Maren. 

I see any of those 3 working with Claire.  My favorite is Julia.