I know that statblocks/character sheets for many if not all of the iconics have exist in various adventure paths or other things. My question is, are there statblocks for all of them, even the APG/UM/UC classes, and what sources can they be found in specifically?
I think they will all be in the upcoming book "NPC Codex"
Iconics have statblocks but they vary depending on the source.
All the APG iconics are available in the Master of the Fallen Fortress module. Valeros, Kyra, Ezren & Merisiel statblocks are also in the latest Free RPG Day adventure.
There are specific PDF to download on the Paizo website with statblocks for the fighter, cleric rogue & wizard iconics at level 1, 4 and 7. You can also download the statblocks for ninja, gunslinger & samourai iirc.
Got fallen fortress and scarlet sun and those pregen packages, between them though still missing Seltyiel, Amiri, Lem, Lini, Sajan, and Seoni. Oh well, maybe Free RPG Day next year will incluce them (though I dunno if that's exactly a balanced party...)
One of the problems with statting iconics is that they are created with the rules available at the time. Valeros created with just CRB could be very different than Valeros with CRB, APG, UC, and UE. Repeatedly updating statblocks with every hardcover release would be tedious and time-consuming (assuming you wanted more than just the level 1 stats).
I started creating 1-20 statblocks for the iconics using published modules/APs as sources but only got as far as Valeros, Amiri, and Harsk. I tried my best to keep them to the rules available at the time so in their case just CRB. It's a lot of work to be sure. My goal is to keep going and add more iconics as time permits.
Cool, and fair enough on the amount of effort it takes.