IME, like gsammo79 said, for the bridge, the 500T sits somewhere in between a Distortion and a Custom. Black Winter might work but is a step further away, IMO. Depends on the guitar type which gets closer. The Distortion in a Les Paul IME sounds sweeter in the mids and highs and the low end was thicker. The Custom was closer in the 500T mids and had the bottom end chucnk, but much brighter on the top end.
For the neck 496R, I'm not sure what Duncan would be closest to that. The 496R I had had a lot of chime and sounded like a loud PAF. The closest I've experience like that were a Burstbucker 3 with an A4 installed, or a Duncan 59 with an A4 installed. Duncans that 'sound' most like it are a Pearly Gates (or maybe Jazz), but those lack the output. I haven't tried the Distortion neck - maybe that does it. I have tried the Black Winter set in my Les Paul and while the neck is clear and even, it lacks the character, mids and chime the 496R had in the same Les Paul.
What guitar are they going in this time? For me, the Distortion and Black Winter can sound very different in different guitars (the Custom was more consistent for me in different guitars, e.g. Les Paul vs Floyd shreadstick).