Just to clarify some things: I did not originally rip the models from the game; this was done by someone else at my request. The only things I can take credit for are cleaning up each rider and making them ready for pepakura unfolding.
Personally, I and most of the users on these forums use cardstock (I use the heaviest cardstock my printer will take) as the base that we work up from, but it all depends on your skill level;
Black Tony Starks has shown what can be done with cardboard and it looks absolutely fantastic:
Iron man Heavy Artillery Armor. If you feel more comfortable using cereal box card, then by all means go ahead.
If you like, I can modify the Double render and remove the headpiece so its looks closer to Skull(its all I can do to his render for the time being) and upload that; the other little details you will have to take care of.
As I have said before, I am still hoping that Double does get his own game, with better character renders to work with in the future.