Oddly enough [name]Marian[/name] was my grand mother’s name and has been in our middle name list since she passed the month before we conceived our boys. Like [name]Laurel[/name] though I don’t cary for [name]Mary[/name] so I am torn on it as I know once given a name takes on its own life with the owner and I might end up calling my girl [name]Laurie[/name] or [name]Laura[/name] or [name]Mary[/name] without loving it you know?
I am so sorry to hear of your dear son.
You have a beautiful naming style!
For girls I like [name]Monroe[/name] for you or as previously suggested, [name]Marlow[/name]/[name]Marlowe[/name]. I also like the thought of [name]Lorelei[/name]/“[name]Rory[/name]”. From your list, [name]Rowan[/name] has been growing on me.
I may receive backlash for this, but I actually prefer [name]Ellis[/name] for a girl far more than for a boy. I know of a girl with the name though. Some boy names I can see for you are… [name]Heath[/name], [name]Shepherd[/name], [name]Pierson[/name] or [name]Whitaker[/name]. For girls I like [name]Monroe[/name], [name]Marlowe[/name], [name]Sheridan[/name], or [name]Channing[/name]! 
So I think we are decided on names for these twins finally…
I am 31wks tomorrow and last set of twins were delivered at 36 so not a moment too soon!
[name]Ellis[/name] Ames A… - EAA
Alternate: [name]Easton[/name] Ames A… - EAA
[name]Reverie[/name] [name]Rue[/name] A… - RRA NN “Revie”
Alternate: [name]Rowan[/name] [name]Rue[/name] A… - RRA
Not too far from where we were months ago but living with these they feel right.
Ack… and then I search popularity on [name]Easton[/name]… back to the drawing board for our boy alternate. 
@dali137 - This is a long shot probably, as I know most people don’t like this name. But as a back-up for your boy, have you considered Estlin? It’s what E.E. Cummings’ second name was (the E.E. stands for [name]Edward[/name] Estlin) and it’s on my list. When I saw [name]Easton[/name] it reminded me of that, and it’s similar enough to [name]Ellis[/name] that it might be a good alternative for you. 
And I think it’s stunning with either [name]Reverie[/name] or [name]Rowan[/name].
You could also consider [name]Eamon[/name], [name]Ian[/name], [name]Owen[/name], [name]Eben[/name], or [name]Westley[/name]. I’d suggest [name]Reverie[/name] and [name]North[/name], but I think there’s still a lot of buzz around the Kardashian baby.
I love the idea of using [name_u]Ellis[/name_u] for your boy, as it sort of echoes [name_m]Emmitt[/name_m]. A tribute of sorts.
[name_u]Rowan[/name_u] [name_u]Ainsley[/name_u] is gorgeous. I’m not such a big fan of [name_f]Reverie[/name_f], though. I’m also not a huge fan of [name_u]Rowan[/name_u] [name_u]Rue[/name_u], it’s a little hard to say. Plus, anyone with an R impediment would never be able to say her name - I only say this because I have a little brother named [name_m]Robert[/name_m], who said his name as “Wobeht” growing up and used his middle name instead because he was embarrassed.
Forgot to post too that the official working names are…
GIRL
[name_f]Reverie[/name_f] [name_u]Rue[/name_u] A… - RRA - nn “Revie”
ALT: [name_u]Rowan[/name_u] [name_u]Rue[/name_u] A… - RRA – though we are looking at other middle names…
BOY
[name_u]Ellis[/name_u] Ames A… - EAA
[name_m]Eamon[/name_m] [name_u]Bran[/name_u] A… - [name_f]EBA[/name_f] - nn “Ames” – [name_u]Bran[/name_u] is a family surname.
Firstly I’m sorry for your lost and congratulations on the twins I hope everything turns out well for you.
To be honest [name_u]Sullivan[/name_u] [name_m]Archer[/name_m] and [name_m]Emmitt[/name_m] [name_m]Erving[/name_m] sound very masculine, distinctively male, thus I would use names that are distinctively female. Female names with a slight masculine twist names like [name_f]Willa[/name_f]. So from your list my favourite choice is [name_f]Laurel[/name_f], because [name_f]Laurel[/name_f] fits the bill and works with the retro vibe of [name_u]Sullivan[/name_u] and [name_m]Emmitt[/name_m]. [name_f]Laurel[/name_f] is a lovely choice. To be honest I love the combination [name_f]Laurel[/name_f] [name_u]Rowan[/name_u], so feminine. I also like [name_u]Arya[/name_u] but prefer [name_f]Aria[/name_f]! Also this makes the combination feel less ‘[name_m]German[/name_m]’ I also like how [name_f]Aria[/name_f] [name_u]Grey[/name_u] sounds very jazzy and sweet.
Suggestions:
[name_f]Thora[/name_f]
[name_f]Margo[/name_f]
[name_f]Beth[/name_f]
[name_f]Elizabeth[/name_f]
[name_u]Marian[/name_u]
[name_u]Evelyn[/name_u]
[name_u]Meredith[/name_u]
[name_f]Bronwen[/name_f]
[name_f]Elspeth[/name_f]