The PAF Joe, I've never used, but I'm sure it's nice, because the kinds of pickups Joe Satriani usually goes for are lower in output, but much much fuller in overtones.
My formerly main guitar (which I used to until my pwn-tastic Vigier arrived) was/is equipped with an X2N in the bridge and a Norton (not an Air Norton, sorry Petrucci fanboys) in the neck. I found the Norton to be a very nice complement to the X2N and not overwhelming in any way, just very focused and very fat. Also, those two pickups seem to work well in most 5 way switching situations, you can get some REALLY nice bell-like strat tones from splitting either as well.
Also make sure you get 500k pots with those pickups, because the detail while rolling the volume down is amazing, can go from almost completely clean up to the full volume without any sacrifice in clarity at all.