WMLeeBo pointed you in the right direction by giving you the link to Swift3D V3 that can be found on the erain site. Swift3D is one of the easiest 3D programs to learn and it's purchase price is quite reasonable for what you get. I would look into the standalone version for what you want to do.
As for a plugin to use your 3D objects and scenes in Flash, you might say that's what Swift3D is. It was created for the very purpose of converting 3D objects into vector art for use in Flash. V3 now has raster output as well, so that's a little extra icing on your 3D cake.
Check it out and let us know if you have any more questions.