you need the not-yet in existance php runtime , so yes you gotta distribute all the php & gtk dll's and any required libraries , you can pretty much stick them all in the one folder if you like , just write a custom php.ini to suit that setup.
I think the current realistic minimum (with 4.3.4) is about 3.2 Mb of files short of custom compiling a minimalist PHP & php-gtk.
MVC is the current buzz in web application architectures. It comes from event-driven desktop application design and doesn't fit into web application design very well. But luckily nobody really knows what MVC means, so we can call our presentation layer separation mechanism MVC and move on. (Rasmus Lerdorf)