If I understand right, you have asked for fullsize Cosplay items. These are going to be
expensive. Just the helmet alone is going to be in excess of $250.00 not counting the labor for the designer's time.
Beyond that, Shapeways terms of service prevent production of fullsize weapons. The Netherlands government won't allow exporting of weapons except for miniatures less than 10cm long.
Third, there
are copyright issues that must be considered. Even if
you only use the item for "personal use", if a designer charges you for the work, they still can be sued for violating the copyright. Shapeways terms of service explicitly state.. "Upload only 3D models and designs that consist entirely of content you created yourself or you have the permission and rights to use." Any reputable designer is going to want you to prove that you have permission to replicate the copyrighted material.
You'll have to do some legal research. There may be some exception if you design and build your own items (but I know that Disney for example doesn't allow that), but asking some designer to take on a legal risk is likely not to get many responses.