I have two suggestions, assuming you proceed roughly as outlined in your
original post.
1. Start with /community
A new community website [4], it can be a place for people to ask
questions and discuss php in general - no one uses IRC anymore.
and use it to build and coordinate the dev team for this new php.net
website. If you do a good job and the conversations and culture develop
nicely then the scope of topics can expand as you already planned. It
could be a success, providing something I think PHP needs, even if you
don't reach all the other goals in your project.
2. Don't use a frontend framework. There's so little stability in this
area that you should plan to own long-term maintenance of whatever you
use, so it's better to start with your own, picking the ideas you like
from the work of others.
