I would go for the Mule myself (and actually have chosen the RR/Mule combination for a custom LP I have on the way later this year!) - the AIV mag lends it a wonderful airiness while being smoother and more tubular than the extremely defined Riff Raff neck.
You could also consider the Stormy Monday neck for an even more open and delicate tone courtesy of the AII magnet. I believe Slash's signature pickups have AIIs in though I haven't tried them myself.
Unpotted gives you the purest PAF experience - more open with astonishing top end detail. Of course, feedback is a concern at high volume levels, but if you can control it, the tone is incredible. Note the unpotted BKPs won't give you microphonic feedback, just easily bloom into harmonic feedback.
With that said, the fully potted pickups are still absolutely "legitimate", and might even be a better option in a bright guitar.
If you want a halfway-house option, BKP can lacquer-pot your pickup (instead of wax), which only partially permeates the wind, giving you a pickup tonally not that far removed from an unpotted pickup but less prone to feedback.