The base Piston unit comes with 128GB of Solid State disk, but you can upgrade to a 256GB version for $340 or 512GB for a whopping $750 extra. The Piston will come with 8GB of RAM and a 3.2GHz AMD quad-core processor. It will use Radeon 7000 series graphics and support up to 3 monitors and, of course, it will run Linux and use Steam.
On the surface it seems a bit pricey to us, but it would seem that there is significant interest in the Steam box and this certainly isn’t the least expensive option. Right now, it is important that someone just do it and not keep talking about it; as that is the only way that the Steam Box concept is going to move forward.