I'm currently working on a rocketeer costume, and I'm currently building the rocketpack. I lucked out and found boots, jacket, and helmet on eBay. The jacket isn't perfect, the middle top button is out of place by a couple inches, but for the price and it being leather, I'm happy. I'm making the rocketpack out of craftfoam, using pepakura pattern I found at heroes workshop. It's coming along pretty well, but I'll have to reinforce a couple places. I plan to build a battery powered smoke machine, and put LEDs in the rocket engines to give it the flame effect. I don't have a harness drawn up up, but I'm going to try to make one with some marine vinyl I bought. It would be greatly appreciated if someone couple give me an idea of the belt size on the harness. Right now I'm thinking of making it 1" wide, and 3D printing the buckles to fit. I mocked up a buckle and printed it, but it's not quite right, the size looks wrong to me. I'll probably scale the buckle pieces up a little bit so they look better.