I would recommend initial try them and no studs. The winter compound (assuming its good and I see no reason to doubt it) are as good and some conditions better than studs. You can add them latter if you feel they are needed.Based on all I've read, I will try and go with the Heidenau K37S Snowtex, and fit some studs to them, probably from Grip Studs.
I have run Bliazks on our Passat for 15 years and zero need for studs, its another cost and a wear out item (and the grip studs are $1 each, I put about 120 on each tire).
The Ural has been very solid and predicative (granted I have studs).
If you do have to go studs, you link it up chart wise and it gives a tread depth. As my pusher had worn a bit, 1100s were safer, otherwise I would have gone with 1200s. Knobs may allow the 1200 easy.
The key is to stop screwing in right at the point the stud base plate is a hair below the tread. That both sets them not to come out and does not over penetrate .
We had one of the 90s Bronco that was supposed to have anti lock (used and it came with a set of studded winter but not winter compound tires) Said anti lock never cycled. Studs wore out, to much tire wear to allow a re-stud, I put on Blizzaks (that is a Rear Wheel Drive rig vs the Passat front). Whalla, anti Lock worked on ice Totally convinced, not even a hint of anit lock acion with studs, full tilt boogie with the Winter compound Blizzaks.