The wpf is already quite low, so even if you wear a lot more armor, you're probably not going to notice a good difference in accuracy in-game, though.
Head armor has 2x the effect on wpf, and gloves have 4x the effect. Even with both, it doesn't amount to much, and simply testing out the weights quickly on the duel server is the easiest option; whatever is comfortable for you is best. My thrower has a 2.7 helmet, 11.1 body, 0.5 gloves, and 2.9 boots, and the accuracy penalty is not harsh even as a pure thrower.