RatRig is the closest, right now. And with the "hybrid" X might be worth it? Sadly I got the 3.1, before the 4 came out, so I'm missing the super-speed on that.
Though, the customizer at the mothership let's you customize the whole thing to whatever size you would like, it sadly doesn't take into account the added rigidity required and doesn't bump you up to 3030 extrusions like I'd expect.