It's important to have less than 108AR vs fire. If you have more than 107, you'll take less than 57 damage from Judgement, so PI won't do max damage. On the other hand, if your AR is too low, you'll need Protective Bond to keep you alive, and that means more work for the emo, so aim to have your AR vs fire as high as possible, up to a limit of 107.
Since rangers have +30 elemental armor and 70 base AR, Armor of Salvation and War Supplies bring them up to 115AR vs fire. To get below 108, your Dhuum armor should be non-max: 61AR, which can only be crafted in The Amnoon Oasis. Do not use anything else to boost your elemental armor, but you can use a Bow Grip of Shelter and Stalwart Insignias for protection against the skeletons.
Anyone except ranger can use a fire shield, and wield a Spear of Warding. (If the Emo prots mesmers, mesmers with Blessed armor need to switch from Blessed armor to a non-Blessed set, such as a spiker set)
If it's your job to die at Dhuum and come back as a spirit, your health should be as low as possible so that you die quickly, so your Dhuum armor should have 5 superior runes. As a spirit, your health is fixed at 500, so the -75s will no longer affect you.
As the emo (assuming you are glitching Dhuum rather than dying), you still want low health so that Dhuum will target you.
The SoS or SS (whoever has PI and is staying alive) should have normal health, only reduced by the superior runes used to do your job.
Emo does not need a special weapon if you are staying alive; just use your normal staff and wand Dhuum.
Everyone else should have a Zealous weapon: bows for rangers since they can meet the Marksmanship requirement and do extra damage, and spears for everyone else. The inscription should be "Don't Think Twice".