I have a Demon in the bridge of my SG X with a rosewood fretboard that sounds like it was made for it. Its big, full and open with bite. And palm muting gives me unholy chug. I have the same pup in the bridge of my Gothic SG mated with a '59 neck, but this guitar has an ebony fretboard. The '59 sounds great, fat and vintage in a Sabbath vein. The Demon however sounds real thin compared to my other Demon loaded SG X.
If your SG has a rosewood fretboard then I think any duncan pup will sound great. If its an Ebony board you might have limited options.