NetBeans has decent support for PHP, HTML, JavaScript and so on, including decent debugger support for PHP. It might be worth a gander.
Then again, you have to consider; if the toolset you've got works for you, why change it? Sure, you want the best tools you can get, but realistically, if you're happy with your current suite, you're not going to want to go messing around changing things around unless some part of that suite is (or becomes) horribly deficient.
