Define pure STR? As in a 36/3 build with 12PS and 11IF?
Stick to siege, or failing that play in battle where there are minimum 60 players and stick to the front.
My STR character uses a Great Helm with Hat, Black Whisby Gauntlets, Heraldic Transitional Armour, Strange Light Boots, Heavy Bastard Sword.
It honestly works wonders and with that fast of a weapon you don't really care about the low wpf plus armour. If you want something slower but more damaging swap the HBS for a Claymore.
The Flamberge is too expensive for my taste and I would rather sport the armour to exploit the fact that I have 93 HP. However, a lot of people underestimate the reach on it so if you can manage it, go for it, it can just harder then you think to use it ( a few people do really great with it though, like George from Shogunate or Random Dude from Fallen or Passion from Blackrose).
