Help with Diver Halloween Costume

[thinkxingu]

OK, we're going to a family Halloween party and I plan to be the diver from Finding Nemo, my wife will be Darla, my son Nemo, and my daughter the starfish.

But I need help on the diving gear--anyone have, or know where I could find, broken/cheap diver's gear. I have the snorkle, mask, balaclava/black shirt/pants (will be worn to school, no wetsuit!), and flippers. Need (I think), the regulator, tanks (may make my own, given the weight), and...what else?

Thanks!