The web design industry is over-saturated - Everyone and their dog has decided in the last few years to become a web designer, due to the relative ease of starting down the path.
The job can be incredibly frustrating, clients can be incredibly annoying, and, more importantly, there is a chance that you'll lose any love/passion that you had for working with websites quite quickly, turning it in to a chore, rather than something you enjoy doing.
I know this sounds negative, and I could just be coming across as jaded (which is possible, I've been doing this a long time), so I feel I should tell you that there are positives - It can be incredibly rewarding and satisfying, and sometimes, just sometimes, you'll find clients who are a delight to work with.
RE the language choices: To be honest, either path will allow you to do whatever you want - the only limiting factor will be how many bells and whistles (or other fancy stuff) you can build in to a site without either JS or PHP. Which is why most people, even dedicated back end developers, know and understand JS (even if it's just the basics).
You need to decide WHAT exactly you want to do within the industry, what your ultimate goal is, and tailor your educational course to fit.