What program is good for PHP development on Mac?

i am looking for a good program to do php development in. i am starting to learn more php and i am looking for a program that will give code hints and auto completion to help me along the way. i currently use dreamweaver cs3 which has great html support, but the php side isnt helping me much. ive also downloaded a trial of zend studio which has great code hints and completion but i feel like its lacking a lot that dreamweaver has. i also cant find out how to preview my file after i edited it, when i run it, it will only tell me if ive got errors and not show me a preview. do i just have to direct to it on localhost? ive looked into coda from panic, and there program has a nice ui and good sql hints, but not much else for php. i also used aptana which looked amazing but the app seemed so confusing i didnt know what was going on. im being picky i know, but im just curious about what others are using. thanks!