OEM pads come with all necessary hardware and copper grease. If you buy aftermarket pads, be sure to order a hardware kit as well. I personally really like PBR/Axxess pads. I have PBR MetalMaster on my 2.5RS and like them better than stock. Noticeable difference in braking performance. PBR Ultra pads are supposed to be even better, although I have not tried them. I run MetalMasters on all my cars.
I changed original pads on my 2.5RS at 92k miles. Probably could have gone longer. It all depends on the kind of driving you do.