ViaCAD has iges, step, sat and many other file formats available.

The only thing what i don't like is when exporting from MoI with
one format and the model is standard "black" color it also comes
in real black color into ViaCAD. But i have this problem also with
Autodesk Software, like 123D Design or Inventor Fusion...

You may try also a beta to see what file format fits best for your
worklflow.

I did this also in the past.

http://masterviacad.com/beta/beta.php

Regards
Stefan