Down to 4:
[name]Jacob[/name] [name]Alan[/name]
[name]Owen[/name] [name]Alan[/name]
[name]Aiden[/name] [name]Alan[/name]
[name]Reid[/name] [name]Alan[/name]
**Sisters are [name]Olivia[/name], [name]Addison[/name], and [name]Ella[/name]…
Help us decide!! [name]Alan[/name] has to be the middle name!!
I vote for [name]Reid[/name], second choice [name]Jacob[/name]!
[name]Reid[/name], then [name]Owen[/name].
Good luck!
I love [name]Reid[/name] as well!
With [name]Olivia[/name], [name]Addison[/name], and [name]Ella[/name], I love the idea of [name]Owen[/name], [name]Aidan[/name], and [name]Reid[/name]! I think they all work very well. [name]Owen[/name] is my favorite, followed by [name]Reid[/name]. I just think they sound so great with your girls. I love [name]Aidan[/name] (this spelling–[name]Aiden[/name]'s not bad, I just prefer the closer-to-the-original [name]Aidan[/name]), but it’s so overdone, and I think [name]Addison[/name] and [name]Aidan[/name] are a bit too close for comfort.
Have you considered [name]Samuel[/name]? I know you said this is your final four, but when I read the title of your thread it just struck me that I hoped [name]Samuel[/name] was on it–I think it fits so seamlessly with your girls! If not, it’s fine, I just figured I’d suggest it. 
I think [name]Olivia[/name], [name]Addison[/name], [name]Ella[/name], and [name]Samuel[/name] are just lovely, though.
[name]Love[/name] them all! I think I prefer [name]Owen[/name] [name]Allen[/name].
I feel like [name]Aiden[/name] is too close to [name]Addison[/name]. [name]Jacob[/name] [name]Alan[/name] sounds good but I prefer [name]Owen[/name] and [name]Reid[/name] to [name]Jacob[/name]. [name]Owen[/name] [name]Alan[/name] is a little rhymey, which could be cute. But I would go with [name]Reid[/name] to have a different initial than the others.
[name]Reid[/name] or [name]Jacob[/name] sound best with [name]Alan[/name] in the middle spot. [name]Owen[/name] [name]Alan[/name] both end in “n” and [name]Aiden[/name] and [name]Addison[/name] are too matchy for siblings. Personally, I would choose [name]Reid[/name] because it’s less common than [name]Jacob[/name].
I like [name]Reid[/name] [name]Alan[/name], with [name]Jacob[/name] [name]Alan[/name] as my second choice.
I absolutely love the name [name]Reid[/name], [name]Jacob[/name] would be my second choice.
[name]Jacob[/name] [name]Alan[/name], it’s my favourite, I did contemplate [name]Aiden[/name] for a couple of seconds before I saw [name]Addison[/name] and I think they are too similar for siblings. So [name]Jacob[/name], I think it’s lovely.
In this order:
[name]Owen[/name] [name]Alan[/name] - love the way this flows by itself AND with the other names
[name]Reid[/name] [name]Alan[/name] - [name]Reid[/name] is such a strong name.
[name]Jacob[/name] [name]Alan[/name] - I love the name [name]Jacob[/name] but I think [name]Owen[/name] and [name]Reid[/name] are nicer with the girls.
[name]Aiden[/name] [name]Alan[/name] - To sound-alike to [name]Addison[/name]
[name]Jacob[/name] [name]Alan[/name] is my favorite.
[name]Reid[/name] is my first choice, [name]Owen[/name] second.
My vote is for [name]Reid[/name] [name]Alan[/name]! I feel it goes well with siblings and it flows the best in my opinion.
I love [name]Reid[/name]! I think it sounds good because the names of your children descend according to the number of syllables, lol! [name]Olivia[/name] - 4, [name]Addison[/name] - 3, [name]Ella[/name]- 2, [name]Reid[/name] - 1. I think it works! Plus my daughter had a little [name]Reid[/name] in her preschool class last year and he was a sweetheart, so I have good associations with that name
My favourite is [name]Reid[/name], my second favourite would be [name]Owen[/name].
I vote for [name]Reid[/name] too!
[name]Owen[/name] or [name]Reid[/name], not a fan of the other two but love these!
[name]Reid[/name], then [name]Jacob[/name]