Recommend an IDE for Windows

I already use and am happy with a variety of text editors (vim, emacs, ultraedit, jedit, Homesite) depending on my needs, but I would like recommendations for a PHP specific IDE that will run on Windows XP. Specifically I am looking for something that can help with debugging, provides efficient code browsing (functions, objects, etc) across multiple files in a project, easy browsing through proper mappings to a development server/local server, and hooks to PHP reference/help/website. Needless to say, standard features like syntax highlighting, block formatting, etc. are a requirement. I've been looking at Zend Studio and Nusphere PHPEd as primary candidates. However, I have a short window to buy something (fiscal year issues) so any comments on these two editors (separately or in comparison to one another) or other tools I should be looking at would be greatly appreciated! c -- Chris Lott <chris.lott[AT]gmail.com>