In regards to the direction for install, the slots and holes don't matter. What matters is the orientation of the vanes in the rotor. If the car is moving <---- this way, then the top of the rotor's vanes (as seen from the left side (driver's side for us southerners)) the vanes should be /////. As if the vanes were "flinging" the air away from the hub as they roll. Not "catching" air. Like a squirrel cage fan. Oh geeze, this link might work better:
http://www.racingbrake.com/v/images/disc_rotation.jpg

If the vanes in between the rotor's halves are straight, then put them on the way you think they look the coolest.

Nice brakes. I'm sorry I didn't catch who made the rotors, care to post?