Go back and find the person who recommended you get two Russians and smack 'em upside the head. If they aren't trying to kill each other already, they will be soon. You should just separate them into their own enclosures now, BEFORE there is blood shed.
Definitely 2 males. They may be fine for a short time together but they will probably very soon begin fighting. One of them will claim their territory for his own, become very dominate over the other attempt to run him off through chasing and often violent biting and ramming. It would be best for both of them to keep them seperate.