BBEdit version 9.3 was released yesterday. Many changes but, it includes extensively revised support for PHP.
Best of all specially formatted Ctags files can now be used to provide function signature auto-complete, similar to that from clippings.
As such I've knocked up a version for Zend Framework, which can grab it from the downloads page.
As it says there, this is a one afternoon, first draft so make sure you subscribe to the RSS for updates. Let me know if you have any issues.
(Know problems are a lack of reference back to source file and line number, but I'll get that fixed asap.)