I know how much a full license of Autodesk AutoCAD costs for Windows, so I can only imagine how much that must cost for Apple..
In a way, it would be nice if Autodesk would have some kind of free trial, so that the pros (I used to draw at one point and still do a bit here and there) could bring the word out to design departments, to re-tool to Apple computers.
I always had a feeling that doing CAD on Apple is going to be much faster.
It got to where they were at R14 and at work I had an apple G4 and they just dropped support.
As far as your build, I saw some interesting solutions in the other Porsche thread, I think that's a 914, if I'm not mistaking.