I cannot remember the sites since I do mine own renders. No I do not accept commissions. I have too much on my plate with GMing, writing two books (fantasy novel and atheist handbook), working at home for the YVO, housework, and getting mine own renders done.
However, if you do a Bing, you may find some persons who will take your idea and render it for free. All they would ask is to have the rights to use the 3D file for other projects. I have found such sites with persons who will do such when I have been browsing the WWW. Do a search.
Also if you do a Bing for "free 3D ray tracing software" you can find many, many things dependent upon your skill level. Blender is the best FOSS out there. But it has a very steep learning curve. Here is a sample Bing:
free 3D ray tracing software.
Here are some other links:
Bryce (for $20, it is well worth it)
DAZ StudioBlenderPOV-RAY (kind of like writing a program)
Modelers
Blender (yes, Blender also models. It also makes cgi movies)
MeshMagic (never tried)
Sculptris (I have this one. It is great for those who know how to sculpt clay)
Wings3D (this one has been around for about 20 years)
TinkerCAD (without internet, won't work, but is an free online version made by AutoDesk)
MandelBulb3D (if you are into 3D Mandelbrot fractal sets)
If you do searches you should plenty of free stuff out there ranging from comically crapy to tremendously sophisticated. Just depends on your skill level.
rmfr