From the announcement:
The Lawmen and Outlaw gang are now ready for pre-order. Each set consists of 7 metal 28mm models, gang rules card and bases sculpted by Steve Saleh.
Release date is April 20th and we will be shipping pre-orders prior to the release date. Desperado and Cowboy gang pre-release details expected in the next 2 weeks; these sets are also released April 20th.
The DEAD MAN's HAND game is also available to order. As with the figures, it is released on April 20th but will ship prior to the release date.