if it's just a one off and you have some experience already in php, then sticking with that might be a good plan.
if you see this as an ongoing evolution and want to explore a framework and language that has some incredibly elegant approaches to the distinct problems and challenges faced in most web applications, then getting into rails could be a game changer for you in the long run. what tends to happen in rails is that the gruntwork goes away, and you're left focusing just on what is unique to the tech you're building. additionally, rails imposes architecture that helps an app over time actually become more and more focused, and accessible, rather than more spaghetti-ish.
once i got into rails, and over the fairly mild initial learning curve, it has been like working with a fine caligraphy pen vs a leaking ballpoint.