1. Unarmed Attacks in the Rulebook: The fact that "Unarmed Attacks" are listed as a parent category for both Gauntlets and Unarmed Strikes on the weapons table supports the fact that the damage increase from the monk's "Unarmed Damage" will apply to both gauntlets and unarmed strikes. (PHB116) It is referenced as unarmed attack progression in Dungeon Master's Guide "class abilities such as the monk’s special unarmed attack progression."(DMG207)
2. Monk's Unarmed Damage: As in the player's handbook, a monk's unarmed strikes are versatile, and the monk's Unarmed Damage applies to all unarmed attacks. The monk's Improved Unarmed Strike allows them to use various parts of their body for unarmed strikes, including fists, elbows, knees, and feet. (PHB41)
3. Gauntlets of the Talon: In the case of the Gauntlets of the Talon, the relic power explicitly mentions that it treats you as a monk of five levels higher for the purposes of AC, unarmed damage, and the ki strike ability. This means that when wearing these gauntlets, your unarmed strikes, including those made with the gauntlets, benefit from the monk's increased damage. As well as they can be Bludgeoning or Slashing. (MIC103)
4. "Amulet of Mighty Fists: This amulet explicitly mentions it grants an enhancement bonus of +1 to +5 on attack and damage rolls with "unarmed attacks and natural weapons." Since gauntlets are considered unarmed attacks, Gauntlets would indeed benefit from the enhancement bonus provided by the Amulet of Mighty Fists. (DMG246)
In summary, the damage increase provided by the Amulet of Mighty Fists, Monk's "Unarmed Damage", and the "Gauntlets of the Talon" does include the damage from the gauntlets themselves, It benefits from the monk's Unarmed Damage as specified in the items descriptions. You can use this information to explain to others that the monk's damage increase is not limited to traditional unarmed strikes only but extends to all unarmed attacks, including those made with gauntlets, kicks, elbows, knees, and headbutts.
D&D 3.5e - Magic Item Compendium: Page 103
GAUNTLETS OF THE TALON [RELIC]
Price (Item Level): 4,000 gp (8th)
Body Slot: Hands
Caster Level: 20th
Aura: Strong; (DC 25) transmutation
Activation: —
Weight: 2 lb.
These elegant gauntlets are made of a silvery metal and have a scaly surface. Each finger is tipped with a long talon made of sapphire.
Provided that you are lawful good, lawful neutral, or neutral good, gauntlets of the talon grant you two primary natural claw attacks that count as magic weapons for the purpose of overcoming damage reduction. Each claw deals 1d6 points of slashing damage (if you are Medium).
Relic Power: If you have established the proper divine connection and already have levels in the monk class, you are treated as if you were a monk of five levels higher than you actually are for the purposes of AC, unarmed damage, and the ki strike ability. This benefit doesn’t stack with similar benefits (such as from a monk’s belt). Also, you can treat your unarmed damage as either bludgeoning or slashing damage (chosen each time you attack).
To use the relic power, you must worship Bahamut and either sacrifice a 3rd-level divine spell slot or have the True Believer feat and at least 5 HD. If you sacrifice a 5th-level divine spell slot or have the True Believer feat and at least 9 HD, the gauntlets also function as ghost touch weapons for the purpose of attacking incorporeal creatures. In addition, you gain a +4 bonus on grapple checks.
Lore: It is said that this silvery set of gauntlets was fashioned by Bahamut himself, then given to the master of a now-defunct order of monks (Knowledge [religion] DC 15).
Members of the order’s inner circle eventually discovered the secret of their manufacture, but they managed to make only a few additional sets before their order was destroyed by followers of Tiamat (Knowledge [religion] DC 20).
Prerequisites: Craft Wondrous Item, Sanctify Relic, righteous might.
Cost to Create: 2,000 gp, 160 XP, 4 days.
Fun Notes:
1. Enhanced Gauntlet of the Talon: The existence of a more expensive version that allows similar functions to stack, akin to the monk's belt, adds another layer of customization for characters who focus on unarmed combat. This provides players with the option to invest more resources for increased benefits.
D&D 3.5e - Complete Divine: Page 97
Gauntlet of the Talon: It is said that this silvery spiked set of gauntlets was fashioned by Bahamut himself, then given to the master of a now-defunct order of monks. A character wearing gauntlets of the talon effectively has natural weapons that deal 1d8 points of slashing damage and count as magic for the purpose of overcoming damage reduction. If a monk dons the gauntlets of the talon, she is treated as if she were five levels higher for purposes of AC, unarmed damage (which now counts as slashing), and the monk’s ki strike ability (this function stacks with the similar functions of a monk’s belt). Gauntlets of the talon function as ghost touch weapons for the purpose of attacking incorporeal creatures. Finally, the wearer gains a +4 bonus on all grapple checks. To use this relic, you must worship Bahamut and either sacrifice a 4th-level divine spell slot or have the True Believer feat and at least 7 HD.
Moderate transmutation; CL 11th; Sanctify Relic, Craft Wondrous Item, righteous might, creator must worship Bahamut; Price 20,000 gp; Weight 2 lb.
2. Superior Unarmed Strike Feat: The "Superior Unarmed Strike" feat from the Tome of Battle (Page 33) is a great find. It offers an additional way for characters, especially monks, to further boost their unarmed damage, effectively dealing damage as if they were four levels higher. This can significantly amplify their combat effectiveness in unarmed combat situations.
These additional options highlight the richness of character customization in D&D 3.5e, allowing players to tailor their characters to specific themes or playstyles. It's always rewarding for players to explore different sourcebooks and discover these hidden gems.