Hi there!
I know one can purchase some special weapons with golden orders. But I’m wondering: will this only give me one example, or one example plus the ability to purchase more of those guns with silver orders?
Also, what would be your recommandation of which golden guns are best?
You will be able to choose one out of the 4 seasonal special weapons, and you will get only 1 single gun. Personally i decided to get the Berdan rifle for the soviets, its ALWAYS an 1 shot kill, no getting downed, instant death and i dont regret chosing this gun. Since i choose the berdan rifle, i cant tell you about the other 3 guns 
(sorry for my bad english)
I chose the Pedersen device for the US, semi auto gun with 40 bullets in the mag. Great for clearing the mid range with your assault squads. Its super accurate and can sustain for a long time.
Just be patient. Don’t get the first one you see. It’s a long game, long campaigns, and you have several great guns to choose from, as I understood it all.
Scav_Sergei made a great comment there.
All the best
That Pedersen device sounds like a gun worth waiting for; 40 rounds in it and if you get the ammo backpack you’re really golden.
Got Berdan II too and kind of regret it. While it’s a powerful OHK rifle you get only 20 ammunition with it, the big ammo backpack gives you 2 extra or something 
I would replace it for something else, like an old Geweher, unfortunately it’s not possible.
I got the schmeisser mk36 iii smg
It’s a nice laser pointer with no recoil but only a 20 round mag
I got ythe PEderson even tho I wasn’t playing Normandy yet - never liked the single shots as an idea much.
The Pederson is an OK weapon - it fires fast and has lots of ammo - but it has an intermediate cartridge so it is never less than 2 shots to kill.
I took Padersen after gold order from this season and it’s silly weapon (in good way, haha).
Fantastic RoF +
Almost no recoil +
Whole idea is crazy +
Low Damage -
Very basic iron sights -
Pistol soul in rifle body.