You could literally just look up 3d printing services- they should be able to tell you suitable plastics, make sure they know it’s to be waterproof! The plastic is waterproof but that doesn’t mean the structure will be. I think most folks would do it in ABS and acetone it to seal if need be.
(I would offer but I’m not that good!)
TBH it doesn’t really strike me as a 3D printing job, unless you want something really specific that you can’t find on the shelf.
Wrong forum or not you got me looking at 3D printer on Amazon.
I so *NEED* One!
I’ve had mine for a few months. I spend most of my time with it either printing out more printer parts, or swearing at it, pretty rare that I get a part I’m totally happy with. It is cool though.