You should be able to get it off their site or other places online. It is a very well done 5.1 mix, as are all of them. Included on the disc are 5.1 mixes of Nil Recurring as well, which I feel has some of the best 5.1 tracks Wilson has done. It will likely be very difficult to find in stores. They have a DVD coming out that was done in high def, so I would presume that means they will be releasing it on Blu-ray
WooHoo!
It isn't going to be hard to find, just expensive. $106.99 This includes a DVD, but I don't see anything about it being DVD-A and I don't want to spend that much if there is a DVD-A coming out later like FOABP did.
I'd say start with either
In Absentia or
Deadwing. Those two tend to be the most well known and popular. Get the 5.1 albums if you can. They have both DVD-A and dts tracks on there.