it would help if you post a little more about what you need done? Mainly is it organic or not. Many designers only work on 1 or the other and those that do both probably charge differently for which it is.
if you look in my shop(click go to shop button) you will see all my models are non organic. They can all be broken down in to exact mathematically definable shapes. Youknowwho also models in this way to what I can see. baroba on the other hand does mostly organic models.
any other information is helpful but at least let us know what type of modeler you need.Follow me on twitter http://twitter.com/mctrivia or my blog at http://4ddice.blogspot.com/
I have one photo of one of the magnets. To answer the above question, I would say my shapes are organic, since they are both going to be in the shape of animals. I made this prototype out of bakelite clay.The other one will be a cow.
that example is kind of in the middle. It is not easily broken down in to mathematical components but being essentially 2d it would not be hard to do so. Now if you wanted the parts to look like the organs that would be a completely different thing.
As an aside if you make a model you can always use your camera and something like http://www.123dapp.com/catch#catchApps to make a 3d model of it. results will never be as pretty as a cad modeler can do but if the model is complex then it is the cheapest method.Follow me on twitter http://twitter.com/mctrivia or my blog at http://4ddice.blogspot.com/