Why don't you develop on Linux? This would result in less bugs on production server. You can easily install Ubuntu on Windows using Wubi (
http://www.ubuntu.com/download/desktop/windows-installer[
^]).
Alternatively, you can install cygwin and PHP package on Windows to get a Linux-like environment. However, cygwin doesn't support case sensitive file name unless you tweak a registry key.
See
http://cygwin.com/cygwin-ug-net/using-specialnames.html#pathnames-casesensitive[
^] for details.
I presume tweaking this key would make Windows filesystem case sensitive - which should satisfy your requirement, without the need to install cygwin.
Good luck!