The requirements depend on you boat size.
for your 4M assuming you can do more than 7 Kts
from memory, would be port & starboard plus an all round white.
As far as wiring goes, if your not planning to use them much you can get battery powered ones that bont need any wiring.
As far as needing them, I agree that you should have them as even if you not planning to go out at nioght they are still required to be used in poor visibility.