It's a large question as Rus Armies often included both the now settles Scandinavian migrants and various ethnic Slav populations.
Also, the period is by convention usually divided into two succinct period, the Era of the Princes (Christian) Rus and the Pagan Rus. Unless you were collecting both armies I think you would have to make a decision on what sort Rus force you were looking at creating.
Onto manufacturers- each with a few pics to give you some idea:Drabant Line- available in the UK from Old Glory:
https://www.oldgloryuk.com/28mm-dark-ages-range/53/224/536/554For Early Pagan Rus Armies the range of Drabant Vikings sold by Old Glory could easily be pressed into service as well


Drabant Line:have no Cavalry bit the sculptor seems to be working through his ranges, based on Saga as far as I can tell so maybe there's hope for Era of the Princes type mounted Druzhina? It is worth keeping one eye one their
Facebook page as all the new releases appear there first:
https://www.facebook.com/groups/2063656313935447V&V Miniatures:
https://vminiatures.com/28-mm/rus/Again, the V&V Vikings could be pressed into service in Early Pagan Rus Armies
I have to admit that I really don't know much about V&V. I've heard a few people say that the miniatures can be a little fragile as they are cast in resin but I cannot personally comment:

Gripping Beast has the most extensive range of Rus by far. You have a choice between Early Pagan Rus, Era of the Princes (Christian) Rus or even 13th CE Medieval Rus.
A couple of pics from each:
Gripping Beast Early Pagan Rus:


Gripping Beast Era of the Princes (Christian) Rus:
https://www.grippingbeast.co.uk/shop.php?p=category_products&category=51&page=2
Gripping Beast 13th CE Medieval Rus:
https://www.grippingbeast.co.uk/Medieval_Russians_Tribal_Warriors--category--145.html

Again, the very extensive range of Gripping Beast Vikings could be pressed into service as Vargazi in all except the 13th CE Medieval armies.
It is also worth mentioning that many Rus warriors were employed by the Byzantine Empire at Varangian Guards. Many of these soldiers would have travelled back to their homes with much of the armour they had worn in Byzantine Service or perhaps had similar armours made when they returned. Anyway, if not then the spread of culture would certainly have spread armour styles around. Many ranges such as Crusader Miniatures, Gripping Beast do Varangian Guards of which the less flamboyant miniature could be pressed into service also.
Hope that helps?
