The Akg K812 is now listed for sale on a Swedish store. Exact same price as the HD 800. It doesn't say if they actually have them in stock or if it's a pre-order. Either way it seems it's getting closer to release now.
As far as I know nobody makes USB cables without the power pin. Therefore it's unreasonable to expect them to make their own production run of cables without power pins just for the dacs in order to deal with a problem only a minority of users might experience.
It's held in high regard because it has earned it. Apart from the treble, which isn't as bad as many make it seem, the HD 800 makes sounds no other headphone near its price point can. I was hoping the K812 would destroy it since then it'd finally get some real competition. But that doesn't seem to be the case, so it'll remain competitively priced when stacked against the best everyone else has to come with.
I used to have a Pioneer VSX-2021 and heard a clear upgrade when compared against a Hegel HD10 and Violectric V800. It was actually that receiver which made me abandon surround sound altogether, because music always lost all its energy when I used it, even in direct mode compared to the separate dacs. I'm completely happy now with a couple B&W CM8, two subwoofers, stereo amp and Muses Edition dac.
Surround receivers for the same price don't have dacs nearly as good as what you get in the Essence One. There's so many parts and license costs involved in surround receivers that you have to pay quite a bit before you get one with great dacs in it.
I don't know where you live, so I don't know which regional store would be relevant. I'm in the EU, so Custom Cable is one alternative there. As for the US I'm not too familiar with the sites that would stock it.