I'm hesitant to upgrade and/or infuse my gear b/c I have the nagging feeling the weapon/armor will suck (or if I trade a boss soul for a special weapon). Example, I traded for the dragonrider halberd and then found it was too heavy to use. My guy walked in slow motion. A few scenes later I traded for the spider sword, which apparently can slow enemies down. I tested it out a few times by spitting the web stuff out and then it broke after three swings. WTF? Anyway, I'm just trying to find a good armor and weapon upgrade/infusion. My guy is a sorcerer-fighter, using the witch robes, firesword, drangleic shield, longbow+7, and sorceries. I'm looking for a good spear and armor set. Should I just upgrade the witch robes too?

thx for help