Hi Bonehead,

I think you'll find the "ideal CAD" program to create those kind images would be ArtCAM Pro, but it comes at a very high cost!
I have an earlier version of ArtCAM JewelSmith & one of the training models is of a lizard/gecko, along with flowers, etc.

Your next best option might be to look at Silo...reason being is that some of those very models at VectorArt3D were made with Silo.
Here's a link to the Silo Forum...read the whole thread to understand how he's doing it.

http://www.silo3d.com/forum/showthread.php?t=8869

Of course all of this will depend on what other types of models you plan to make in the future?
Having both MoI & Silo to cover all manner of possible modeling options may be a better choice in the end.

Hope this helps, Colin