The best option would be to pick
a framework and learn to use it. I may get flamed for this view, but I don't really think it matters as much
which framework you choose, just choose one and learn to use it well. Invest time in to learning with it on a throwaway project.
You will not be as productive end-to-end on day 1 as you are with your current tools - that's OK, because after learning a framework, you will be more productive than pure hand-coding for any web-app of any complexity. You'll likely be safer, because there's been more effort put in to most frameworks to help protect against web attacks (SQL injection in most cases).
Learning a framework will teach you to think differently about your development process, as well as introduce you to a community of like-minded developers all using the same tool. It will help you develop a development process.
You'll get to the point where you're comfortable and productive, and then you'll start noticing limitations in whatever framework you're using. That's the time to start looking for another one, and either jumping over to using that, or more ideally, looking at what ideas and components you can reincorporate in to your current tech stack.
I love Grails (Java) because, while it's niche, it makes model-drive development a snap. I create classes, identify relationships, and the system can generate the db layer (tables, etc) for me automatically. There are ways to do some of this in PHP, but the language itself makes this extremely verbose. However... I still use PHP (now using zfkit as a basis) for some projects, and have done some .Net work where it made sense (on an MS-only project, to be precise).
It's easier to jump around now because I've spent time understanding not just the particular languages involved, but thinking about how web apps are commonly abstracted (MVC, service layers, db layers, etc). Understanding those common patterns makes it easier to swap between frameworks and platforms as needed.
Gentle plug - I'm working on a starter kit for zend framework - zfkit.com - which aims to bring a somewhat better 'out of the box' experience to ZF (at least from my perspective). You can download and it's bundled and preconfigured to use the Doctrine ORM tool. That said, if ZF and Doctrine rather make you say "huh?" it may not be for you just yet. :)