I even built you a set up from KEH Check out the BGN Prices the only one I couldn't find on BGN was the 1.9, but if you wait it out you can always find one for a great price =)

http://www.keh.com/camera/Mamiya-645...990412020?r=FE
http://www.keh.com/camera/Mamiya-645...090391340?r=FE
http://www.keh.com/camera/Mamiya-645...990177310?r=FE
http://www.keh.com/camera/Mamiya-645...000190000?r=FE