I would check out Heralds of Ruin (link below) as their 7th edition Kill Team rules blew
GW's out of the water. I felt they did a great job using 7th as a game engine to create a pretty good skirmish game that allow players to use more of their
40K collect (in terms of allowed units like terminators) than the actual
GW rules. They have an 8th edition set out now. I don't know if it will be better than
GW's, but I think their's will be far more play tested the way most players play. So I would hazard to guess it will better. Their only issue is those players that have to play "official" rules.
http://heralds-of-ruin.blogspot.com/p/kill-team-rules.html