what was your final solution? I follow the same workflow you mentioned in your post in order to send clients regular updates on drafts of work.
…..it’s slow work!
I’m mostly working with HDV footage in FCP. I work with it natively at 1080i50 which has proved to be pretty quick rendering although yields large file sizes.
I export out an uncompressed QT reference (which is also pretty quick) then within QT PRo I load the reference file and export a ‘small’ H.264 QT file to send via yousendit.com. I export a ‘small’ h.264 file (559 x 315) to try and keep the final file size down. My file sizes are small but it does take a long time to do. At least FCP is freed up!