Since
Nicholas is majorly overused at the moment, I'd lean towards
Nathaniel...
Other Ns...
NoahNiel (
Neal,
Neil)
NilsNoelNelsonNorman (you said names- not usable names)
Ned NgaiNgoziNikolaiNorbertNortonNobuyoshi
Noriyuki
Nobumichi
Noboru(a whole bunch more Jpns. names if you want them)