Hi techmike. When you replace your pads you don't need to replace your rotors. Your rotors have a minimum safe thickness at which they are no longer capable of properly stopping the car. Rotors can be resurfaced until you get close to this minimum thickness. Factory rotors can be drilled or slotted but they weren't designed for that.
ECS Tuning has an excellent selection of brake parts. Including Hawx brake pads. I have heard good things about the Hawx pads from fellow BMW owners. Definitely worth looking into IMO. The prices seem reasonable and they have packages available as well.