Vikings? Leather and Fur would be the materials of choice, perhaps the Scaled Armor. Most Vikings I would assume would not wear metal armor, as it would cause them to drown if they fell overboard. Not sure if the Vikings used different armor on a boat than when they attacked on land.
Probably not. Most vikings didn't even wear armor, altough many of those who went plundering did (they didn't wear armor at Stamford Bridge and subsequently lost the battle but they wore armor at Fulford and won).
I'd go for no armor with the Steel or wolf helmet, a guard, iron/banded iron, hide or steel shield and a war axe. you could also use the iron battle axe. The rich ones were able to afford chainmail and swords so if your character can afford it then guard armor and an iron sword looks the part.