I think all of them are perfectly usable, except maybe [name_m]Kees[/name_m] due to pronunciation misunderstanding. My pick would be [name_m]Anders[/name_m], but that’s simply because that’s the one I personally like the best.
My favorite name is [name_m]Vince[/name_m] and my second choice would be [name_m]Anders[/name_m]. Those are great name! I also like [name_u]Schyler[/name_u] and Marten.
[name_u]Schyler[/name_u](like “sky-ler”) -i like it. I love the sky sound
[name_m]Dirk[/name_m] - not a fan if I’m honest. Sounds a bit harsh and like dirt…
Marten -i like it. A solid name
[name_m]Anders[/name_m] - love this! Strong but free and fun
[name_m]Kees[/name_m](like “case”) -i think the pronunciation might confuse people if your not in a country where Dutch names are familiar, but I like the sound and look of it
[name_m]Vince[/name_m]or[name_m]Vance[/name_m] -i like [name_m]Vance[/name_m]!
[name_u]Schyler[/name_u] is really awesome and I like this spelling better than [name_u]Schuyler[/name_u]. It makes the sky sound more intuitive for me.
I also like [name_m]Anders[/name_m] a lot, and for some reason Marten spelling is making me really enjoy the name. I’d agree that all are intuitively pronounced save for [name_m]Kees[/name_m] (which is a pretty cool name but might be better off as a middle name).
My favourite from your list is Marten. You might also like:
[name_m]Edwin[/name_m]
[name_m]Laurens[/name_m]
[name_m]Cor[/name_m]
[name_m]Rens[/name_m]
[name_m]Wessel[/name_m]/Hessel
Zeger