Looking for :
Exterior form design
Presentation with renders.
1 working prototype.
It will take lots of revisions to get there. So the designer has to be patient and accommodating to changes/variations as well as improvements on the way.
Only serious professionals are requested with expertise in 3D printing and prototyping.
I have provision for 3D printing (large printer) at my office. It is easier and cheaper to send your completed files to me and I can print the prototype here, instead of you doing it.