Also, make sure to keep in mind the nicknames, since that is what kids usually end up going by. Do you like Joe? Sam? etc.; and think about when he writes his name, or it is called out in class:
Joe Broome
Sam Broome
Dom(or Nico?) Broome (FYI: My friend's son is Dominic, and everyone calls him Dom)
and so on


Personally, I really like the nickname Niko/Nico, like you said, and I think Dominic Broome and Nico Broome both sound great. I say don't worry TOO much about the sound of the full name, b/c you seldom will call him that (except when he is in trouble, probably.)
Sometimes, for no reason, I'll call the boys their full names ("Joel Kieran" and "Evan Matisse") just b/c I think it is a bit disappointing that we spent all that time trying to figure out their names, then never really use them!

Honestly, all the names you chose are really nice sounding, so no matter what, your kid is gonna have a decent name! (And I LOVE Samuel Dawson. Very classy.)

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