To OP.
Find it by yourself (hint t1-t4 chapter inf rewards and from PvE/PQ questing.. mainly PvE part of the game). Just joking.
Here's a link to my topic where I've posted pictures and descriptions.
viewtopic.php?t=11978
My old topic from link above details the names of the items.
My experience with these items is based on about 2+ year observation while playing both Marauder and Chosen.
Models are nearly the same with Marauder having the limping mutated arm and lack of two hand weapon animation set (which I wish I could do on marauder but that's another story).
Those looks didn't break any animation, didnt twist your character model or jinx it in anyway.
Was sporting those awesome setups on both my marauder and chosen back when official servers were still kicking and loved every second of it. Especially wearing full plate helmet with horns pointing downwards and holes in face part on my Chosen that looked like regular t3 marauder helmet.
Two quotes that were reply straight from devs in here :
Strykarr : On this server, the other faction see your alternate appearance too. That's why we try to fix those kind of items.
My reply would be : those items don't break anything. just look at the pictures. and belive me when I say I've been playing it for 2+ years and didn't get any game/server crash, animation didn't do any weird stuff, no issues at all.
And since enemy faction can see your alternate appearance anyway then having marauder helmet on chosen ain't gonna fool anybody as much as t4 chosen sporting t1 armor looks. Marauders can't swing 2h swords/axes or use 1h weapon + shield. It's really that easy to discern which dude is running towards you - his weapon is giving him away. If he has 1h weapon in each hand/one hand is mutated it's a marauder.
Torquemandera :
Aesthetics are important to many people, myself included and on live chosens were running around with deformed WH coats on and all sorts of crap.
{I agree on this part. remove those broken/twisted abominations - but leave marauder helmet on which didnt break NOTHING}
A sovereign helm, as Im sure you appreciate, is not for tier 1 classes to run around with.
{not possible for a char that didn't get to wear it so i don't see how could T1 char could ever wear that}
I dislike the animations of DoKs so dont play them as nothing can ever be done about that.
You will not be disappointed with what you will be able to look like in the near future, either in actual armour sets or appearance, of that I can assure you but it will be appropriate for the classes so no Blackguards in bikinis.
I've stated that i doesn't break any model related stuff on chosen or marauder (had 2+ years of experience using it), none of it is sovereign its just armor looks and just fun to have.
So that's my part and my internal scream of pain and sadness that still echoes in my soul for getting the answer of sorts that stated - nope, no more marauder helmet on your chosen ever again...
On a sidenote :
I really hope I didn't offend anyone and/or made anyone angry because that wasn't my aim.
Just griefing that I won't be able to make my chosen to look like a marauder or my chosen to look like marauder (at least partially) ever again.
While on a subject of cool items : how are those screaming cat tavern Gotrek and Felix items drops going? accessible? incorporated into the game somehow since the old city siege is waaay old history?