RDF is very basic what comes to what gear you can need.
You should only need upgrades that are clearly for your class and role. Needing on tank stat gloves as DPS, while not even wearing gloves, is still ninja.
Armor types (beyond level 40):
Plate: DK's, Paladins, Warriors
Mail: Hunters, Shamans
Leather: Druids, Rogues
Cloth: Mages, Priests, Warlocks
Stats:
Strength: DK, Paladin, Warrior DPS's. Plate tanks as well, if combined with high stamina or other tank stats.
Stamina: Main focus on tanks. Healers and DPS's as well, if combined with other appropriate stats.
Agility: Hunters, Enhancement Shamans, Rogues, Feral druids. Druid tanks as well, if combined with high stamina or other tank stats.
Intellect: All casters. Enhancement Shamans and Hunters, if combined with Attack Power/Agility.
Spirit: Priest and Druid healers.
Crit/Haste: DPS/Healers.
Hit: Tanks, DPS's.
Expertise: Melee DPS's, Tanks.
Dodge/Parry/Block/Armor (highlighted with green): Tanks.
MP5: Healers.
While in RDF, you should forget end-game near BiS-level item priorisations, and go to what classes use in their basic level itemization.
So no leather needing Retribution Paladins, Fury Warriors or Death Knights, or Caster Druids or Shamans needing cloth.
World of Warcraft is a PC game, so you should have easy access to keyboard. So, use it and talk with other RDF members, if there's an item that you can't need, but could use as an upgrade. You'd be surprised to know if you talk and ask people nicely, good things could happen, but don't hold it against them if they decline your kind offer/question.