I know it's been a while since you addressed this subject, but did you ever solve your problem?
We are at a crossroads where we need to deicde which direction to take. We have recently ( last 2 years) started using Autoplant. There are lieks and dislikes about it, but one thing I really like is it's ability to generate isometrics complete with mat'l list. Because our structural dept uses Revit, and also several other reasons: I get the impression Revit MEP is more user friendly, it produces more attracted 3d views, one of our other offices has a subtantial library, we are thinking of switching to Revit. However, if I cannot easily produce isos like I can with Autoplant, that is a major drawback.