Distant Horizons of Lands Long Forgotten and Tales Untold
The martial classes are extremely common among Iodian adventurers, except for paladins. True believers are rare everywhere. Fighters are by far the most common, at almost half of all adventurers in Iodi. Rogues aren't terribly uncommon, but casters in general are quite rare. Druids and clerics are the most common casters, followed by bards. Wizards make up less than one percent of adventurers, but monks, sorcerers, and warlocks are even rarer still. Monks practice psionics, a rare but not unheard-of discipline similar to magic in some ways.
The most commonly practiced forms of magic are (in order) healing, fire evocation, and necromancy.
Please check below for errata that may pertain to your character:
Arcanists are more common now than they have been in the past (and there's plenty of conspiracy theories relating to the ShiKaen Invasion on why that might be), but they're still quite rare. It's worth thinking about where you learned your craft.
The Teras Vin in Ael Gilliurst train wizards but generally demand life service from members of their order. Not entirely unheard of for their junior scribes to teach themselves magic on the side before they're read in and then jump ship once they have what they came for, though.
The Navigationists in Narvi specialize heavily in divination to the exclusion of all other disciplines, but offer training and research resources to any with the aptitude in exchange for contract research work.
Ever since a massive subterranean ruin was discovered near the city, the formerly small port town of Nar'Qashi has been attracting spellcasters, occultists, and scholars of all walks as the local Razgauthen Khan is paying for the recovery and translation of texts found below. Due to this influx of spellcasters, dozens of related SIGs have sprung up in the area.
Aside from the above, there's also a handful (estimated half a dozen or less) of hermit sages in Iodi. Unsurprisingly these hermits are typically not fond of company, but it's theoretically possible that a caster could learn their trade from one.
If there's an alternate class archetype you like I'll consider stuff published by WotC, either in Unearthed Arcana or in physical books.
Monks are quite rare in Iodi and the only organizations of them that exist are those of spies and secret police (referred to as Jasvsyh), usually in service to the Padishah. It is possible (though unlikely) to learn these skills outside of such an organization, but the association is so strong that almost all Iodians assume all monks are spooks. The only people who know better are the savvy citizens of one of the big cities where these organizations operate. There are less than 200 monks in all of Iodi.
Monks may choose thieves' tools or poisoner's kits as a tool proficiency instead of an artisan's tools or musical instrument.
Monks' abilities are psionic in nature. Instead of ki points, they have psi points. The save against your psi abilities uses your Intelligence modifier rather than Wisdom. If a monk ability is normally based off of your character's Wisdom score, it is instead based off your Intelligence (including multiclassing requirements).
Monks have access to the Psionics skill at first level.
If you gain your first level in warlock while in Iodi, you will not know the specific identity of your patron though of course you may still choose whatever patron "type" you like.
It is common knowledge that iron hurts warlocks (among other creatures); iron weapons deal an additional 1d4 fire on a hit, and every round touching an iron item with bare skin deals 1d4 fire damage (minimum 1 fire damage if the contact is immediately halted).