According to rawr, you should stick with the harpoon. It suggests you put a 10str/10crit gem in your helm, stamina/strength in your chest instead of AP, straight strength in the bracers and weapon, 10str/10crit in your boots, a 10 all stats in your legs instead of the haste/sta gem, 2 strength gems in your belt and 10str/10crit & a strength one in your gloves.
As far as enchants go, you'll want the melee head enchant from the knights of the ebon blade, the sons of hodir insciption of the axe for your shoulders, haste or agi on your cloak (they're about equal). I'd go for expertise on your bracers, icewalker on your boots, AP/crit patch for your legs and precision (20 hit) on your gloves.
The best advice though would be to get
rawr yourself and have a look and see what gear changes would work out best for yourself.