Any maps needed should be in the adventure path itself, for the players they should use blank hex maps for outdoor mapping and graph paper for indoor dungeon mapping.
My group uses colored pencils to make outdoor maps look nice. If you don't have access to hex paper but can print download the players guide to kingmaker AP from piazo it has a blank hex sheet.
The map packs from the company are just the same ones in the adventure path books but in some cases blown up a bit and on individual sheets or posters, they are not needed but do look cool. Again no extra maps are in them just reprints of whats in the adventure paths themselves.
As for mapping in general, keep in mind that it doesn't have to be exact. If they want, they can just draw boxes for rooms and connect them with lines to mark corrdors and doorways.
In the end, as long as they can use it to navigate effectively, they're good.
The benefits from drawing the map out in detail are sometimes better visualization of enemy positions and available terrain. That's where the accessory map packs, flip-mats, and so on are useful; you can see where there may be obstacles or positions to get higher ground attack bonuses. But you don't NEED them.. as Paraxis noted, the AP volumes have all the maps you need.. what you can do for your players is help make clear to them the things you can see on your map that maybe were not in the room description. Is there a pile of crates? They can climb up on that to get an advantage. Is there a fallen column? That can provide cover as a low wall, possibly. That sort of thing.