> One version is FCP HD Studio 6
There's no such thing.
"Final Cut Pro HD" was the nickname for Final Cut Pro 4.5 (nicknamed as such because it was the first FCP version to handle HD), which does not work on Intel Macs. If I remember correctly, there is a "Crossgrade" version that works on both PowerPCs and Intel Macs, but that's Final Cut Pro 5.1.
"Final Cut Studio" was the combined name for the package that came with Final Cut Pro 5.
"Final Cut Pro 6" came as part of the package called "Final Cut Studio 2".
You will likely have issues trying to run these older versions on Lion. I would advise getting Final Cut Pro 7 (Final Cut Studio 3). You might be able to get by with Final Cut Pro 6, but I wouldn't put my money on it. Also, if you buy used software, you better make darned sure the transfer is handled properly. The first owner would have properly un-register his copy before you can use it.
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