Marco, Just about any style Magpul stock (and other brands as well) will fit this rifle. There is a catch though. The buffer tube comes in tow different diameters. There is a Mil-Spec size and a commercial size with the Mil-Spec being slightly larger in diameter. When you go to buy a new stock, you will have to choose between the two sizes. The stocks are not interchangeable between the two different sized buffer tubes. Most good quality AR-style rifles come with the Mil-Spec sized buffer tube. However, it pays to check before you purchase a new stock.

That depends on what you want to use the rifle for. Pretty much any of the adjustable stocks today will let you find a length-of-pull that fits your own shooting style, and most are very functional. If you want a nice, clean, lightweight stock, I like the Mission First "Minimalist". I use one on my "everything' AR, and have really liked it.

Marco, I favor the Magpul MOE M-LOK Stock Set. Buds does not have this in stock but, you can take a look at/purchase it here : at3tactical.com/products/magpul-moe-m-lok-furniture-kit-stock-carbine-handguard-grip

That is the AR that I have and I have never felt the need to change the stock as far as function none of the MagPul stocks are any better Pick the stock you like if you feel the need to change. I would say get more mags and shoot the gun like it is (at least for a while)