Usefull Links
The best places to find 3D models for 3D printing
Cults3D - Wide variety of free and paid models
CGtrader - Largest inventory of models, but not necesserly processed for 3d printing, which may affect the price of my services
Makerworld - Good variety of free and paid models
Thingiverse - free models
You can also go through google and try searching for "stl" or "3d printing models" with the name of what you are looking for, and browse through google images.
Send me the link that you find, and I'll get back to you with a quote.