I never really liked the whole "last name as a first name" deal, unless the last name actually is commonly a (variant of a) first name. Middle name, okay,
maybe.
I suggest you name them Daniel and Julia.
After Deezer and me? ;)
Maybe
this topic will give you some ideas, Toad.
Here are some
naming tips of mine.
There are lots of baby names and definitions sites you can easily find online, if you haven't already.
If you use Madeline, I wouldn't give her a middle name starting with an N-sound (the last sound in Madeline) or the letter M (alliteration). Probably something with one syllable –
maybe two – would be good. Some suggestions: Ava, Grace, Paige, Rose. Claire, which you mentioned, could also work.
As for Benjamin, similar deal: no starting with N-sound or letter B. I think it could work with 1-2,
maybe 3 syllables, depending on the name. jmdblazer's suggestion (Robert) isn't bad. I can't really think of anything else off the top of my head that works, I like, and wouldn't make the name "overly biblical" or something.
Congrats, by the way, Toad!