If you have access to a 3D Printer (still waiting for them to be renamed Replicators, myself), you can print off your own Duke Mk.44 thanks to Kirby Downey at MyMiniFactory. Thanks to Bluerunner for pointing it out.
On a related note, Mid7night came across a host of models you can order at Shapeways by Brickinator99, including armor and weapons, as well as a mini-Ghost for LEGO-sized figures.