Looking for the best board for a remote controller/networked controlled robot

Sorry, didn't mean to leave you hanging. I want to build something like this:

Only four legs, possibly a little bigger to hold sensors, or a claw.
Goal is fast though, it be cool to see that thing sprint across the livingroom.
I want to put a couple distance sensors on it, and a mini camera.

I kind of want to put a claw or something that shoots little rockets, something to do with it besides just walk around.

In all, I want some motors that can move quick, but hold a little weight. Sorry, I don't really know specifics.