ostfront.com, they sell everything in reproduction or originals. I have a TON of stuff from them.
tridentmilitary.com is another good place but you need to call them on the phone to order.
watch out for collectrussia, he often forgets about orders and it takes FOREVER to get anything from him. He ships from overseas.
they sell German stuff also.
Opps. I guess I should hasve asked what ERA?? Soviets used the same damn everything from WW2 up till the Afgan war when then finally changed over to new stuff. All links above are pre Afgan war. Some stuff was still used after, like the great coats.
what kind of stuff are you interested in? I have a lot of contacts in this area and I do Soviet & German ww2 living histories/reenacting.