I know what the Steve's Special sounds like - strong bass and treble with quite a pronounced mid scoop. I like the sound for chords, but there's not enough push in the midrange for old-school rock solos; or maybe that's just my sloppy playing.
Didn't Petrucci use it before he switched to the D-Sonic?
As for which BKP comes closest, that's one for the experts. I'm not sure any of the BK humbuckers are designed to do that mid-scoop thing, are they?