Same disc. If you bought the first BD release, you're good-to-go. :)
The difference between the US and UK versions of the film is simply the inclusion of Superheroes in the UK version, btw. There were also some prints in the US that had a Time Warp reprise over the end credits. I know my old...
I mean, if you don't already own it, it's a good deal for the film and the soundtrack CD together. Then again, I think most people who are fans of the film already own both, maybe on multiple formats. (I may have almost gotten divorced over an impulse purchase of the LD box set when it was...