Breed neck and bridge, with something like an FS-1 or SDS-1 (I'd go with the SDS personally) in the middle. The Breed set was made for Steve Vai because he wanted his JEM to sound like a Les Paul - the JEM is alder, generally, and otherwise basically the same spec as any RG, so you should get similar results with your 670. The SDS-1 is designed to be something P90-like in a Strat-sized housing, so in the middle position on its own or split with the Breed set, it should give you some cool sounds in the vein of what you're looking for.
I will say that these pickups, especially the Breed set, is a little more "modern"-voiced, but aimed at more "vintage" sounds, so I think it should work for you pretty well.