Which combo sounds best with my older sons name?

I have a four year old Adriaan [name_u]James[/name_u] ([name_u]Arie[/name_u]) and found out last week that my little expectee for [name_u]December[/name_u] is a boy as well (I’m thrilled since [name_u]Arie[/name_u] has been asking for a little brother since last Hallowe’en). We’ve decided on the name [name_m]Nicolaas[/name_m] ([name_u]Kai[/name_u]) and think it fits well with Adriaan. Now we need a middle name to go with it, we have a common English last name that ends with -er, so none of that. Some we’ve narrowed it down to - and they all have familial ties just like my older son - are in no particular order:

[name_m]Nicolaas[/name_m] [name_m]John[/name_m]
[name_m]Nicolaas[/name_m] [name_m]Gordon[/name_m]*
[name_m]Nicolaas[/name_m] [name_m]Eugene[/name_m]
[name_m]Nicolaas[/name_m] [name_m]Gordon[/name_m] [name_m]John[/name_m]
[name_m]Nicolaas[/name_m] [name_m]John[/name_m] [name_m]Gordon[/name_m]

Other less prominent one:

[name_m]Nicolaas[/name_m] [name_m]Amos[/name_m]
[name_m]Nicolaas[/name_m] [name_m]Elihu[/name_m]
[name_m]Nicolaas[/name_m] [name_m]Thomas[/name_m]
[name_m]Nicolaas[/name_m] [name_m]Timothy[/name_m]
[name_m]Nicolaas[/name_m] [name_m]Robert[/name_m]

We decided on Dutch first names and English, biblical or family names to tie in heritage for middle names. [name_f]My[/name_f] personal favorite is [name_m]Nicolaas[/name_m] [name_m]Gordon[/name_m], but think [name_m]Nicolaas[/name_m] [name_m]John[/name_m] might go better with Adriaan [name_u]James[/name_u]. I’d like others opinions on the matter, thanks in advance!

I like [name_m]Nicolaas[/name_m] [name_m]John[/name_m] & [name_m]Thomas[/name_m]. [name_m]Elihu[/name_m] is interesting, as well.

Adriaan ([name_u]Arie[/name_u]) and [name_m]Nicolaas[/name_m] ([name_u]Kai[/name_u]) are great together! [name_m]Nicolaas[/name_m] [name_m]John[/name_m] does have really good flow to it, but if [name_m]Nicolaas[/name_m] [name_m]Gordon[/name_m] is your favorite I would go with that one.

[name_m]Nicolaas[/name_m] [name_m]John[/name_m] gets my vote - it has a great flow/balance. [name_m]John[/name_m] goes well with [name_m]Nicolaas[/name_m] and fits well with [name_u]James[/name_u] too.

[name_m]Nicolaas[/name_m] [name_m]John[/name_m] and [name_m]Nicolaas[/name_m] [name_m]Elihu[/name_m] are my favourites. I think the former works best in the sibset.