I'm pretty sure there was a version of StudioVision that ran on OS7, but it would have been copy protected (which is why you are asked for a floppy), and I'm not aware of any instances of it without the protection. When Opcode died Jason released a version of StudioVision without copy protection. That's probably the version to use. It wont be the older version, and it may only run on OS9.
StudioVision was the very first "DAW" on a personal computer. It probably came out in 1990, but it might have come out in 89. My memory isn't very good with dates.
The workflow is a bit different than Performer (including Digital), but there are enough similarities that you'll be able to use either without too much trouble. One of my favorite things about StudioVision is the logic that you can employ for modification and substitution of events. It's very powerful, and I've not seen it replicated.
In the most recent versions Opcode added the ability to convert audio to midi, and back to audio. This allowed you to make changes to the audio that previously no other program could do—a precursor to what Melodyne can now do, and of course DP lets you do these things directly now too (under OS X+).
As a side note Seal's first album was produced by Trevor Horn, and they used StudioVision on the album.