I've only confirmed with two of them that we will go for that achievement together. One of which as I mentioned doesn't have the game. So one of my boosting partners, the two of you, and myself can go for the achievement.
I'm sure he would appreciate that, plus the other guy that hasn't confirmed that his interested could be the fourth for that time, that will mean everyone ends up with the achievement .
So if you and your boosting partner send me a friend request I'll keep an eye on my friends list and when everyone is online I'll message you all, set up a party and we can can get the achievement, I doubt it will take more than say 15, 20 minutes if that.