Isometric decision time: what path to take

Ok so I have been working for a week straight to try to solve my depth sorting issue (http://jwopitz.wordpress.com/2008/09/03/absolute-isometric-depth-sorting/) with no practical solution. After reading countless articles on the hows and the whys I am starting to seriously consider a radically different approach: Using 3D to mimic an Isometric perspective.

I have thought about this in the past and decided against it because I thought the learning curve for the open source 3D SKDs out there were too opportunity-cost prohibitive. Well now I know I have blown plenty of time trying to fidget with my own solution to no avail.

I wanted to get some quick feedback from the 3D SDK users out there highlighting a few points :beer2::

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[]I want to be able to use real flash.display.MovieClip classes so that the art can still be based on content created in the Flash IDE. I found this article which seems like PV3D can do this. What about the other SDKs? - http://labs.blitzagency.com/?p=377
[
]I think away3D has the ability to make the camera view appear isometric (based on this article) - http://www.nabble.com/Away3D-vs-Papervision3D-td10872780.html What about the other SDKs? I know for sure that Alternativa3D does this but it is not open source and plans to have server integration which I don’t want to deal with.
[]What are the performance implications of using a 3D engine to depth sort for me vs. trying to manually do what I have been trying to do with an isometric engine (unsuccessfully so far).
[
]I am not really interested in using the FFilmation engine since it lack the performance I want for complex scenes. Of course this could be the case for using a 3D engine as well.
[/LIST]