The items range from logo t-shirts to replicas of clothing worn by prominent characters -- Kazuhira Miller's shirt is included in the lineup, sans jaunty yellow neckerchief. Perhaps that'll be in the next release; Konami and Musterbrand plan to update the line "quarterly and surrounding certain special events throughout the year."
As for the current items: you'll be able to Peace Walk in game-inspired pants starting April 11, when the first pieces will be available online in North America (probably through Konami.com).%Gallery-120381%