Netbeans is a competant PHP IDE. Moreso than eclipse. PHPStorm is just Jetbrain's IDE with PHP support. It isn't anything special but it is more complete for PHP development.
You might want to take a look at PHPDesigner. Probably the better of the 3 for PHP stuff but it might not support theme development as much, although it has the ability to use framework libraries in projects for code completion in a very simple way.