DR1000 -- I don't think it was ever available. It was talked about in some of the pre-release announcements and there was briefly a "pre-order" for it, but I don't think this model ever really existed. I think it was removed before they started shipping real units.
DR1000S -- Currently the only model that you can buy.
DR1000SW -- Will be released "sometime in the future", but nobody really knows when that will be. There's a
form on their site that you can sign up for an email notification when the "SW" model becomes available.