Barbarian - Mead Master's Helm (Head) - +2 str, apply effects of liquid consumable turned into coach to when entering rage 2 times/dungeon (rather than the normal upward pointing horns people envision of viking helms, the horns are on the side downward pointing implying the ability to drink from the bottom like a beer helmet). Maybe since it would usually be bull's strength loaded up in the horns it might need to just be +1 str, not sure.
Bard - Harmonizing Choker (Neck) - +1 saves, +2 damage to party and may physically attack while bardsong active, no instrument may be used,(envision it as a choker with multiple small speaker/megaphone like attachments, it's magically adding background music in real time while the bard sings, leaving their hands open for other activities)
Cleric - Warpriest Gloves (Hand) - May reduce spell healing bonus by up to 10 to improve melee damage bonus by that amount (in coaching room)
Druid - Bowl of Elemental Attunement (slotless) - Druid learns of elemental weakness of enemy 1/rm (sort of a more limited but reusable spirit sight)
Dwarf Fighter - Tossing Harness Armor (torso) - AC +7. Retribution 4. Ally may use an action to throw you to allow melee attack against ranged enemy. (it would allow a player not equipped well for ranged combat to throw a dwarf also not geared well for ranged combat at a ranged only enemy using both their actions for the round. It would be amusing to allow for either automatically dealing the dwarf's retribution damage or making a melee attack, but not sure there's a reasonable way to write that up. Image could be like a side view of plate armor showing something that looks like an ale mug handle attached to the back.) This maybe could work as a slotless armor attachment without the retribution or ac boost too.
Elf - Archwizards Finery (torso armor) - +4 dex, +2 int (this sort of assumes int is going to effect more than just the staves at some point)
Fighter - +2 shot put (thrown weapon) - Use melee to hit bonus. Stun target on natural 20
Monk - Gloves of Overwhelming Power (hand) - Thrown weapon attacks may use melee to hit bonus (not quite gloves of the flying fist, but close)
Paladin - Disorienting Shield (off hand) - AC3, Has a 3-8 damage wheel - On a natural 19-20 enemy AC reduced by 5 on following round.
Ranger - Elemental Quiver (back) - 1/rm Select Cold/Fire/Shock, your missile attacks do +2 damage of that type (does not require using ammunition tokens, effects normal bow shots as well). Sometimes +2 damage, sometimes with elemental weaknesses it ends up more like +7. maybe too strong, but almost certainly giving up good save boosts to get it, so maybe ok.
Rogue - +1 Dazzling dagger (main hand 3-6 dmg wheel) - Damage wheel includes 1 fire damage. Prevent self and 1 ally from being directly targeted by enemy for 1 round (not sure on the wording, but the idea would be it couldn't prevent area or cleaving damage, but could prevent an enemy with 4 separate attacks from using any of those attacks on the rogue and whoever they stand in front of that round)
Wizard - Pyromancer's Robe (torso) - +2 AC, -3 dmg from fire, +3 damage with fire spells, 1/rm may recast a fire damage spell if a higher level spell is sacrificed