hi mate, i am using some 2mm plastic board from the Norwich group (might even have enough for a second JP), it is really sturdy stuff yet pliable enough to bend and cut. I am also using 56mm BT ducting for the fuel cells and i got lots of that you can have. Seriously i knocked this up in just two sessions. I am usings WOF's plans and they are really simple to follow. Believe me i am not spending £200 + when i can make my own as good as this
If you want to make one i can print you off the templates and see what material i got left. I even lend a hand if you want.
I got to still make the rocket (gulp) and add the last few bits to the body but hey its almost there
this way i might even have my costume ready for Jeremy Bullock in November (I still don't have a back plate but i might be able to get away with that due to the jet pack).
btw got the first couple of coats of silver on the bucket and will be painting it this weekend