Integrating flex apps with flash

I've been struggling on actually getting a flex interface to have flash elements in it and I've isolated the various ways to do it with pros and cons. My basic issue is that I want to be able to integrate something that can be maintained in the future as opposed to just doing flash which has not a lot of maintenance capabilities because of the assets and possible pieces of code in the fla.

So what I've worked out is you can do the following:

1. Do a full flex interface with the buttons in flash 9 preview which allows you to actually do stops, gotoandplay and respond to frames based on the flash 9 interface. Downfall of this is NO components from the flex framework, or any components from the flash 8 framework -- the only thing that really works is textfield. Anything else just doesnt work. So for simple buttons this can be cool because of custom glows, etc.
   
2. Implement the buttons in flash 8 and load in the SWF at runtime as a custom component and use flashinterface to communicate with it. The problems are that this now puts you into a language with flash 8 -- so now you have to communicate flash 9 and flash 8.
   

So, the basic idea I can see is that the best option is to do the bottom for full on interfaces that need customization -- the flash 8 can be done in such a way to automate the interfaces and make them kick ass and then the flex class can integrate this high level enough.