Increasing Size for Weapon Dice

[Cyussu]

I am playing a Pathfinder 3rd party game using finalfantasyd20.com/ffd20
I'm playing a Bangaa Pugilist, and we're lv12-14 at the moment. Using PF-only content otherwise. My Damage is currently 5d4 (+1d4 per 5th level) per swing before adding anything else to the mix. (Maths out 5-20 vs 2-20) and a Threat Range of 16-20 (Improved Critical & Keen do not work) And I am not entirely well-versed compared to 3.5e content, so I am having a small issue trying to locate and figure out the ways around it. Impact is unavailable due to the nature of my weapons. That's all I really have, thank you in advance ;3;

[Secret Wizard]

Are you using unarmed strikes?

[Cyussu]

Yes, I am.

[Extra Anchovies]

In Pathfinder, you can't stack size increases on top of each other; a character can only benefit from one actual size increase (i.e. something that literally makes you bigger) and one virtual size increase (i.e. something that makes you act as if you were bigger without actually making you bigger) at any given time. Your virtual size increase is as easy as Improved Natural Attack (Unarmed Strike). For the actual size increase, I recommend a friend or item capable of casting Enlarge Person. I can't recall any plus-two-sizes effects off the top of my head.

[Secret Wizard]

Stonefist Gauntlets are your friend then. I think they are about 15k gold? And treat your IUS as if you were one size larger.

[Cyussu]

@Extra Anchovies: You can't take "INA(US)" in pathfinder. Otherwise, yes I am aware, but I do NOT want to be Large in itself, hence why I am asking for ways other than that. <.<

@Secret Wizard: I can't find that in paizo content

Another note: I specifically said using Pathfinder Content Only. DM won't allow me to use 3.5e content or I would've pulled out getting Glowsteel(Which is 3.5/3.0e content) Cestus for the +1 Damage Die increase (He's already allowed me to use Cestus as Monk Scaling unarmed damage)

Edit: I would like to emphasize, I know a good deal of 3.5e-oriented Monk Shenanigans to make an unarmed fighter worth it's salt. I've made a few flavorful, and 2 min/max'd using different build styles. It's the Pathfinder Content-only lock that is stopping me from making a mildly threatening unarmed fighter in comparison to some of the other classes/archetypes in the FFD20 content

[Secret Wizard]

Sorry, meant Stonefist Gloves: http://www.archivesofnethys.com/MagicWondrousDisplay.aspx?FinalName=Stonefist%20Gl oves

[Cyussu]

Sorry, meant Stonefist Gloves: http://www.archivesofnethys.com/MagicWondrousDisplay.aspx?FinalName=Stonefist%20Gl oves

Why are they so cheap!? Welp, I wonder if I can get my DM to allow me to +1 & enchant them like weapons... XD That much is completely based on DM digression, so ain't much I can work with that.