the coilovers do not have anything for attaching the swaybar endlinks too. rabbits kit has an L shapped bracket that bolts into place utilizing the 2 bolts that secure the knuckle to the strut (or coilover). rabbits kit also includes different (shorter) endlinks that mount to the swaybar and the other end mounts to the L shaped bracket.
In aspect of the strut bar, for straight line driving (also drag racing) a strut bar wont make a difference. However when you turn left or right the vehicle will have body roll, the strut bar stiffens the front of the vehicles suspension (upper strut area). the vehicle in turn is more solid when turning, it wont feel as sloppy or loose. with a strut bar you will feel like you have more control of the car when turning