If you need basic syntax highlighting and auto completion features, Edit Plus is a good choice. You can add more functionality to this for example your documentationa and coding style etc. In other words lot of functionality.
If you need to see how your code works, and preview it on a browser, you already have the answers I guess. But I'll add one more bit to it.
There is a total radical new IDE for PHP made by a co. called Maguma. It's called PHP4EE Studio. Of course, the thing costs. But their light version is free for download. Although it's much error prone on W2K, I am using it quite successfully. Here's the Link www.maguma.com. And hey where did you get PHPEd from? Can you mail me a link or something.
--Rolla