@phleobon i would suggest get a Macbook air instead with the upgrades, but windows laptops are already good enough for PHP development. I already tried the latest Macbook and i dont like its keyboard it feels like you are typing on a touchpad click.
The new mac book pro is smaller. I don't think they offer a 17" laptop anymore. I don't need the portability so I use a mini but I did have a pro for awhile and I used a dock from microcenter that holds the pro on its side and on the bottom a holder for the cables for mouse, keyboard, charger and monitor connections. Worked amazing drop and play but can pull out and be on your way.
Web developing generally doesn't require that much power. I have noticed php storm, more so on start up, uses quite a bit compared. Imo if you do desgin with photoshop, if it will run that your good.