Of the 3 stock from the factory , the Backpacker one is the best , The fact that the barrel can be clipped to the bottom of the stock for transport makes it perfect, it's good to keep things together with a take down rifle .
The standard stock is good , But BORING .
And the Chassis one is like lego , which is fun , but could be a money pit , just ask any AR guy , this one would be great if you want to go the short barrel route.
what follows is about the Magpul backpacker stock only.
The LOP is just right in that it makes it feel less front heavy ,The storage in the stock for a spare mag is nice and the weight of what ever you place in the storage also helps offset the balance to the rear.
It has 4 QD sling points ,[down side is you have to buy them separately,] and can be used to sling the rifle with the barrel in place or clipped under the stock ,very slick to carry in the field , ether way .
The forend has mlok , but only on the sides , for lights or lasers.
Sights , definitely a red dot , something with a little magnification , like 2x or maybe 3x , it is a PCC after all not a sniper rifle , the most fun you're going to have with it will be 50-75m .
Tandemkross do make some good looking fiber optic iron sights , might be worth checking out.
And mags , 3 for sure , 5 is good , 8 is perfect, you should have enough mags to load up a box of ammo .
Most of what I've said has already been told on here ,I'm just condensing it , readers digest style . lol
YMMV.