Logic Pro 8 Must I re-install everything?

Just received my 27" quad-core i7 iMac (with an intact screen, no less). I need to install Logic Studio 8 on this machine. My samples, loops, and audio files are kept on external firewire hard drives, and I'm hoping I can leave them there. Is it possible to install only Logic, Waveburner, and Soundtrack on the new machine? I'd rather not have to wipe the external drives clean, re-install the loops and samples and then have to re-index them etc etc if I don't have to.

And yeah--I know Logic 8 isn't officially supported on Snow Leopard, but it seems to run fine based on what I've read.

Thanks for any insights,

You only need to reinstall the program itself.
The EXS will find its sound content on any drive that you have connected (you may have to activate that option in the EXS' "option" menu, but after a fresh install it shouldn't be necessary). The first load of whatever instrument might take a while, but after that things should be fine (note: the EXS needs to locate the used samples, sometimes it requires user input to select one (of a few) options, once that is done the EXS patch will automatically be updated and hence load a lot faster next time).
Your Apple Loops will have to be re-indexed. To do that, you better delete your Apple Loops index on your new machine (should be in "Machine HDD/Library/Audio/Apple Loops Index") and then drag your Apple Loops folder onto either the Apple Loops application or Logics loop browser. Takes a while, but not all that much. In case you create a lot of Apple Loops yourself, you'll better be off creating an alias or symbolic link to the location you want them to be in (otherwise, all self-created Apple Loops will be saved "somewhere" on the internal drive - quite a not too great approach by Apple, I think).
Further sampler libraries can usally be re-sorted, too, the method depending on the soft-sampler you're using. Refer to the manual (for instance, Kontakt has a database "rebuilder" but also another system-wide thing to tell it where to usually find samples and/or patches).

- Sascha