While I can't help you with a pickup suggestion, I can offer some other insights. Most humbuckers use magnets with a thickness of 1/8th of an inch, regardless of whether that magnet is alnico or ceramic. The only pickups that use differently thicknessed alnico mag's that I've ever personally seen are filtertron-styled, which use 1/4 inch thick a5's if memory serves me. I've never taken a super d' apart before myself (someone who has, please chime in and help us out), but it likely has either a 3/16ths or 1/4 inch thick ceramic (the Imperium bridge, my favorite humbucker right now, uses a 3/16ths ceramic with a thin pad of foam between the frame and the magnet so the magnet really only affects the coils). Another example that dimarzio made with a thicker ceramic was the megadrive humbucker from the 80's. As far as the magnet being glued down, some very gentle persuation with a pocket knife blade or a thin flathead screw driver can easily get past that without damaging the pickup so long as you're careful. I have found, with a little googling, that there are a couple of places that sell thicker a5 humbucker magnets if you ever wish to try the swap. Just trying to help a little, have a good one!
