Well, as I wrote I'm from Poland and I'm crazy lover of the name
JACEK.
FILIP is one of my favorite Polish names. I like also
ALEKSANDER so
Jacek Aleksander would be great. I think the name
ARMIN is amazing although extremely uncommon in my country and not in the same style as
Jacek so he rather wuldn't be
Jacek Armin. But if I were from English-speaking country my son would be
JACK or
HYACINTH. Maybe
Jack FINN,
DECLAN Jack,
Hyacinth ALEXANDER, or
RASMUS Hyacinth or
Hyacinth Rasmus.