[sblock=Concealment]As far as I'm aware, concealment + concealment doesn't give total concealment. In other words, concealment doesn't usually stack to give any greater benefits. Total concealment basically means that you cannot be seen at all. Total darkness with no vision aids or blindness are probably the most common sources of total concealment. So if eyebite hits, you would definitely be able to make a Stealth check, though it would only apply to the target you blinded (unless you had total concealment or superior cover against other enemies).
However, I suppose the ruling on that is up to ukingsken. I have seen things like 2+ squares of bushes between you and the attacker gives you total concealment, but that is, if you will, a 'special' rule of the terrain, and isn't how things work by default.
Superior cover is a little more attainable, probably from the rocks in this battle.[/sblock]