A quick Google search led me to the soundtrack, how about that? I have it downloaded so I can pass it off to the staff for ya.
As for AdaptofVale's request...
..huh.. it seems.. Knuckles' Theme is missing from both Sonic 3 and Sonic & Knuckles? They're in the PC versions, but not the Mega Drive versions. Same goes for the Competition Menu for Sonic 3.
Which one from this you talking about? These I have on my Winamp player: