I will be running on WIN2K. Which packages of cygwin will I need to install?

Get at least the base package, cygrunsrv and rsync (of course).
Also get a decent editor, one that knows about unix/windows/mac
text files. It does not have to be a cygwin-based editor (like vim).

I assume I will need GCC to compile the program.

Not unless you need to change anything. A precompiled binary for
the cygwin environment is included in the package.

Pim