--what version of Unix Perl (Linux vs Solaris, for example) should I use?
That's sort of an odd question - one can't expect to run Linux or Solaris binaries on Mac OS X. The literal answer, then, would be "the Mac OS X version." That's not a very useful answer, though, and I don't think it's what you were looking for.
In a broader sense, the answer to your question is that it's generally easiest to simply use the Perl that's included out of the box. Or, if you want to upgrade to the latest and greatest, just compile the standard generic UNIX version. (As opposed to a more specialized platform-specific binary package such as ActiveState's Perl for Windows, or MacPerl for classic MacOS.)
--any pitfalls I should be aware of when moving from Win to OS X/Unix?
There are probably quite a few, but here's some I can think of off the top of my head:
Any code that makes use of the various Windows::* modules will naturally have to be ported.
Be sure that your scripts have UNIX line endings. Windows or Mac line endings won't work.
File paths are UNIX-like, using '/' as the path separator - not '\'.
Scripts need to be made executable, using either the "chmod" command or Finder.
The standard CPAN shell, rather than ActiveState's PPM, is used to install modules. (See 'perldoc perlmodinstall')
--any related documentation you can recommend would be appreciated
There's very little Mac OS X specific documentation to be had, primarily because all of the generic UNIX-oriented docs apply. For the most part, wherever you find docs that vary significantly from their UNIX counterparts, they're usually referring to MacPerl for older versions of Mac OS.
Searchable archives for this list are found here: <http://www.mail-archive.com/macosx%40perl.org/>
sherm--
