I totally enjoyed the Lollar P90's a dude had in his guitar. Totally different from the P90's in my guitars and way nicer sounding than the Seymour Duncan "hot" I think, P90's in a semi solid tele signature model I played - the SD's were noisy too.
Maybe consider RWRP neck pickup for noise cancelling in the middle pickup switch position. That should also produce a slightly more mellow sound.
I would think that the stock PRS ones should sound good. Possibly mess around with them to adjust the height, lower them, etc. I know it can be difficult to adjust the height on P90's and it takes some innovating. It is also possible to twist off those wood screws that you use for adjustment when lowering the pickups. A really great guitar tech could probably work wonders adjusting those stock pickups. I'd start there. The G P90's are the original ones and a classic type current production set is found by many to sound great.
Good luck with your tone quest.