One way or another you’re going to need a 3D model. If you can’t do this yourself you’re going to need a kind willing sole or you’re going to need to pay someone. I start at £85/hour and generally expect a min. 1 hour.
Then you’re going to need either someone with a 3D printer or a bureau you can upload your file to in order to get a quote and order it.
3dprintuk are really good for commercial MJF or SLS process. You may be able to find someone a little cheaper who can do it on a FDM machine (the cheaper printers you commmonly see when folk talk about 3D printing) – quite a few people with one at home stick their services on ebay. Again, at a cost I could quote it depending on what you want.
Feel free to PM me for my email address to share sketches with if you want a quote.
Cheers, Chris