Bill- I think I understand your question (I visited your website). You have client/producers who would like to deliver their projects to you as a FCP project/movie and then you would go off to digital tape. We have done this a couple of times now and it works really well. We work in 8-bit uncompressed 1/2 hour shows. We export the final show as an 8-bit uncompressed quicktime movie to our SATA raid. It takes about 20 minutes and the file size is about 30 GB. We then dump the self-contained movie to a firewire drive and take it to our dub house.
They copy the movie from the firewire drive onto their G-5 (w/FCP) internal SATA drive then launch a FCP project with the movie as the only asset and go out SDI (AJA io) to any tape format we want. Bingo- no digital/analog conversions and no codec compression issues and we have a digital uncompressed copy of our show!
The key is that your clients provide you with a self-contained movie (you don’t want to start dealing with timelines and individual media files) in the format they want to go to tape with and that you have the matching codec loaded in your FCP system ( I believe Black magic provides all the major codecs). I hope this answers some of your questions.
Jerry